Osman I (Osman Ghazi): the Founder of the Ottoman Dynasty

Osman I, also known as Osman Ghazi or Othman, was the founder of the Ottoman dynasty and the commander of the Ottoman Turks. Later, the Ottoman Empire was founded and controlled by a dynasty carrying his name (first known as the Ottoman Beylik or Emirate). During Osman's lifetime, this realm was a tiny Turkmen principality, but it grew into a global empire in the centuries after his death. It existed until shortly after World War I ended. Unfortunately, little accurate information about Osman has remained due to the lack of historical documents dating from his lifetime. There is not a single written source from Osman's rule that has survived. Osman's life was not chronicled by the Ottomans until the fifteenth century, more than a century after his death. So, therefore, historians discover it very hard to distinguish between fact and fiction in the various legends told about him. One historian even declared it impossible, referring to Osman's life as a "black hole" during that time. Osman's forefathers were descendants of the Kay tribe of Oghuz Turks, according to subsequent Ottoman legend.

On the other hand, many early Ottoman academics consider it a later invention intended to bolster dynasty legitimacy. Many Anatolian beyliks arose in the second part of the thirteenth century, including the Ottoman principality. Osman's principality, which was located in Bithynia in northern Asia Minor, was particularly ideally positioned to launch raids on the weak Byzantine Empire, which his descendants would eventually capture.

Some academics believe Osman's first name was Turkish, most likely Atman or Ataman, and that it was only subsequently altered to Osmān, an Arabic name. Early Byzantine sources, notably Osman's contemporary George Pachymeres, spell his name Ατουμάv (Atouman) or Ατμάν (Atman), but Greek authorities translate both the Arabic form Uthmān and the Turkish variant Osmān with θ, τθ, or τσ. As a result, Osman may have eventually acquired the more distinguished Muslim name. Othman was used by Arab academics such as Shihab al-Umari and Ibn Khaldun, while Ibn Battuta, who visited the region during Orhan I's rule, named him Osmancık. In Turkish, the suffix -cık (or -cuk) signifies diminutive. Therefore he was known as Osmancik, which means "Osman the Little," to distinguish himself from the third Caliph, "Uthman the Great."

Most sources believe that the Ottoman Turks were members of the Kayı Oghuz Turkic clan, who, according to Ottoman legend, fled their original Central Asian country during the Mongol invasions in the early 13th century. The tribe established itself in Anatolia, in the Seljuk Sultanate of Rûm. Other accounts suggest that the Kay clan and the Seljuks migrated to Anatolia two centuries before the previously given period. They departed Transoxiana for Khurasan around 1040 CE to settle near Merv. After 1071 CE, the Kayı clan relocated to eastern Anatolia, ousted among other Turkic families. Later, it joined Sultan Kayqubad I's army and fought against the Khwarazmians, Mongols, and Byzantines who raided Seljuk territory. The Kayı warriors were famed for filling front lines in fights, according to numerous accounts, and their fighting abilities and bravery were among the primary reasons the Seljuks were victorious in many wars. This caused Sultan Kayqubad to designate Ertuğrul, the clan's Emir, as a Moqaddam (Lieutenant) and reward the Kayıs with fertile estates near Ankara they settled and stayed in the Sultan's service for several years. Later, Ertuğrul was given authority over the Byzantine border town of Söğüt in northern Anatolia. In addition, he was given the title of Uç beyliği or Uç bey. This title was bestowed following Seljuk Sultanate custom, which presents the title of marcher-lord on any clan head who comes to prominence and is joined by several minor clans. Ertuğrul, on the other hand, had far-reaching political ambitions. He aspired to grow beyond the territories that had been bestowed upon him. During his half-century as a Seljuk governor, he began invading Byzantine lands in the name of the Sultan, successfully capturing many cities and villages and gradually increasing his rule. Ertuğrul died at the age of nearly 90 in 680 AH / 1281 CE.

Although Osman's birth date is unknown, some accounts claim that he was born on 8 Safar 656 AH / 13 February 1258 CE, the same day when Mongol armies attacked Baghdad, slaughtering its population and destroying its landmarks. However, Osman was most likely born in the middle of the 13th century, probably around 1254/5 CE, according to other sources, such as 16th-century Ottoman historian Kemalpaşazâde. Thus, there is a scarcity of information on Osman's early years. However, the few sources available agree that he was born at Söğüt, which his father Ertuğrul established as the capital of his emirate. Because the oldest-known source on this period was published roughly a hundred years after Osman's death, there is a scarcity of information about this era of Osman's life. In reality, it is widely acknowledged that Ottoman, European, and Byzantine sources are unreliable when it comes to Osman's and his clan's roots. On the one hand, the earliest known records written by the Ottomans all come from the era after Constantinople's capture (1453 CE). On the other hand, none of the Byzantine historians mentioned the Ottomans' origins in their works.

Osman was Ertuğrul's youngest son, according to Ottoman historian Kemalpaşazâde, and he was trained in the traditional nomadic Turkic traditions, learning wrestling, swordsmanship, horseback riding, arrow shooting, and falconry from an early age. He swiftly acquired the abilities described above, excelling all of his brothers in the process. He was also taught Islamic beliefs and inspired by Sufi sheikhs' teachings, particularly that of his master, Sheikh Edebali, and this was reflected in his personality and way of life. In terms of dimensions, the most common and traditional story is that Osman is the grandson of Süleyman Şah, who drowned while on horseback crossing the Euphrates River. Yılmaz Öztuna [tr], a Turkish historian, believes that Gündüz Alp was Osman's grandpa and Ertuğrul's father, and that Süleyman Şah is more likely a name stuck in Anatolian popular memory, and that it alludes to Süleyman bin Qutulmish, the founder of the Seljuk Sultanate of Rûm.

Öztuna adds that Ottoman historians may have attempted to establish a link between the Ottomans and the Seljuks, mainly since the Ottomans arrived on the historical scene claiming to be the genuine successors of the Seljuks. Based on all of this, the lineage that assumed by Osman is as follows: Osman bin Ertuğrul bin Gündüz Alp bin Kaya Alp bin Gökalp bin Sarquk Alp bin Kayı Alp. Other scholars believe that the link between Ertuğrul, Osman, and the Seljuks was created mainly by court chroniclers a century later and that the Ottomans' real roots are thus unknown. On the other hand, some Ottoman sources claim that Osman and the Oghuz Turks are descended from Japheth, Noah's son. Osman's genealogical tree has 52 or more predecessors and finishes with the Prophet Noah himself, closer to fiction than the truth. All Oghuz Turkic peoples, including the Seljuks, are descended from Gökalp and Oghuz Han (who is supposed to be Gökalp's father). Some of what Yılmaz Öztuna brought out in his argument is that the Ottomans were continually seeking to connect or tie themselves to the Seljuks and pose as their heirs, which can be seen in this assertion. In his six-volume of the book Badāʼiʻ az-zuhūr fī waqāʼiʻ ad-duhūr, Egyptian Mamluk historian Muhammad ibn Iyas gave Osman a completely different origin. According to Ibn Iyas, Osman was of Arab descent, born in the Hijaz in 658 AH (1259–1260 CE), and resided in As Safra' near Medina. When the territory was hit by economic difficulties resulting from the Mongol invasions, followed by a severe drought, Osman escaped to Anatolia and resided in Konya, the capital of the Karamanid Beylik. With time, he became used to wearing Turkic clothes, following Turkic customs and traditions, and learning Turkish. Soon after, he joined Emir Alâeddin Ali bin Khalīl's service and became one of his most trusted soldiers. As a result, Osman was rewarded with titles and property, increasing his authority and attracting many men.

Osman's actual year of birth is unclear, and little is known about his early life and origins due to a lack of sources and the various myths and stories that the Ottomans created about him in succeeding decades. He was most likely born in the middle of the thirteenth century, maybe around 1254/1255, according to Ottoman historian Kemalpaşazade of the sixteenth century. Osman's father Ertuğrul, according to Ottoman legend, led the Turkic Kayı tribe west from Central Asia into Anatolia to escape the Mongol assault. He subsequently pledged allegiance to the Sultan of the Anatolian Seljuks, who awarded him control of the Byzantine border town of Söğüt. The link between Ertuğrul and the Seljuks, on the other hand, was created mainly by court chroniclers a century later, and the Ottomans' real roots remain unknown. Nothing is confirmed about Osman's early activity, save that he ruled the territory around the town of Söğüt and conducted raids against the Byzantine Empire from there. The Battle of Bapheus, which took place in 1301 or 1302, is the first dateable event in Osman's life. He beat a Byzantine army sent to oppose him. Osman appears to have pursued a strategy of expanding his territory at the cost of the Byzantines while avoiding confrontation with his more Turkish solid neighbours. According to Stanford Shaw, his first Invasions were against the local Byzantine nobles, "some of whom were defeated in battle, others being absorbed peacefully by purchase contracts, marriage contracts, and the like," as they led from the barren areas of northern Phrygia near modern Eskişehir into the more fertile plains of Bithynia.

Ascendance to Leadership

After his father died about 680 AH / 1281 CE, Osman became Emir or Bey. According to some historians, Osman's rise to power was not smooth since he had to fight his kin for the leadership of his clan. When Osman planned to invade a tiny Greek island, one of his primary opponents was his uncle Dündar Bey, who may have conspired to murder him or revolted against him. Dündar Bey regarded Osman's ambition as a menace that may jeopardize the entire clan. Osman, on the other hand, had to draw his sword and murder his uncle for disobedience. After Ertuğrul's death, a book featuring narrations about Haji Bektash Veli, Osman's younger uncle, became Bey in the Vilayetname. Osman and many other soldiers began planning assaults against Byzantine areas around Söğüt, such as Yarhisar, Bilecik, İnegöl, and İznik, during this period. As a result, the Byzantine Tekfur (governor) of Bursa was enraged, and he despatched envoys to the Seljuk Sultan Alâeddin Kayqubad III, expressing his displeasure with the continuous assaults. As a result, the Sultan ordered Gündüz Alp to bring his little nephew before him, and Osman was apprehended and sent to Konya. Sultan Kayqubad, according to this account, appreciated Osman's bravery and actions and did not desire to punish him; instead, Osman was sent to the Ḥājī Baktāš Walī to ponder his situation. The Sufi mystic welcomed Osman with open arms and then ordered his release, adding, "I have been waiting for someone like him for years." After that, Ḥājī Baktāš Walī covered Osman's head in the Sufi sheikh's Turban and sent him back to Konya with a message to the Sultan, requesting that Osman become the Kayı Emir. As a result, Osman rose to become the clan's head.

Importance of the Osmanic Beylik Location

Osman's Beylik had a considerable influence on his success as a conquering warrior from a military standpoint. Söğüt, his capital, was built on a well-defended location, in the middle of the vital route between Constantinople and Konya. The significance of this location arose as a result of Anatolia's political fragmentation, which gave minor states greater prominence than they had previously. As the Emir of a beylik bordering Byzantine countries, Osman had the chance to devote all of his energies to war and Jihad, following in the footsteps of the Seljuks, to conquer and absorb all Byzantine areas into the Islamic Caliphate. In addition, Osman had the opportunity to expand into western Anatolia, crossing the Dardanelles to southeastern Europe because of the old Empire's weakness and continuous conflicts in Europe. Some historians suggest that Osman's policy of expanding his domains at the cost of the Byzantines was motivated by a desire to avoid war with his more powerful Turkic neighbours. In terms of politics, Osman has shown exceptional ability in creating and implementing new administrative systems in his beylik.

During his reign, the Ottomans made significant progress in settling down in permanent settlements, moving away from the nomadic tribal structure. This allowed them to solidify their position and grow into a great power quickly. Furthermore, the beylik's location in northern Anatolia, close to Christendom, forced a military strategy on the Ottomans, giving them a leg up on the interior beyliaks in terms of growth and expansion. The Mongol invasions and the influence of the Turkoman solid beyliks in southern and southwestern Anatolia were likewise comparatively far away from Osman's beylik. Its closeness to the Silk Road, which connected Byzantine holdings in the west to Mongol-controlled territory in the east, gave it strategic and economic significance. The Osmanic beylik was also the sole Islamic bastion confronting the unconquered Byzantine areas, which attracted numerous Turkomen farmers, soldiers, and Dervishes escaping the Mongols and seeking new lands for economic and religious reasons.

Political Relations at the Foundation of Osman's Sovereignty

According to the Bektashi narration, Ḥājī Baktāš Walī was one of the Wafā'īyyah tariqah dervishes, a Murid of Bābā Eliyās al-Khorāsānī, whose correctness cannot be proven because it was only stated in Bektashi sources, plus the fact that it did not get much backing from the majority of researchers. When Bābā Eliyās died, Ḥājī Baktāš Walī and Sheikh Edebali became two of his 60 successors and grandmasters of the Ahyan Rûm fraternity of warriors and farmers, who had considerable power among the people. When Sheikh Edebali's daughter married Osman, he gained control of the brotherhood and became its new grandmaster. All of the Ahyan sheikhs fell under Ottoman authority as a result of this marriage. After the death of Osman, during the period of his son Orhan, this had a significant influence on the formation and growth of the Osmanic beylik. Some say that Osman's marriage to the daughter of Sheikh Edebali was his first significant political move. According to Kafadar, early in Osman's rule, the young Emir showed political dexterity in forging relationships with his neighbours. Osman's connections were multi-tribal, multi-ethnic, and multi-religious. Perhaps he may have gone with his gut and his political ambitions, not realizing the long-term consequences of the familial ties he established and secured for his son after him. Osman restructured the Seljuk Sultanate of Rûm's political culture to meet the demands of his beylik. In blending Turkic, Islamic, and Byzantine traditions, he was more inventive than his Turkomen neighbours.

The Emir also collaborated with the Byzantine Tekfurs of the surrounding cities and villages. He forged an agreement that his clan would leave their belongings in the Byzantine fortress of Bilecik whenever they moved between grazing areas in the summer. Upon their return, they would give its governor a token of appreciation in cheese and butter made from sheep milk and preserved in animal skins or a good wool carpet. During Osman's rule, this agreement illustrates the cohabitation of herders, farmers, and city inhabitants. Osman's relationship with Köse Mihal, governor of Chirmenkia, was the pinnacle of this Muslim-Byzantine cohabitation. His relationships with other peoples, including the Mongols, who mainly migrated to western Anatolia's boundaries, and the Germiyanid Turkomen, were unfriendly. The Turks disliked the Mongols in general, and the Germiyanids were most likely non-Oghuz in origin. Osman established an alliance with the Ahyan Rûm brotherhood, and the two created structured organizations, each with members who specialized in a specific trade. To protect their rights and the rights of Muslims, the brotherhood took on the task of preserving justice, preventing injustice, ending oppression, adhering to sharia law, dictating good morals, and performing military responsibilities if necessary.

In Anatolia, the Emir formed alliances with newly arriving Turkomen tribes. In comparison to those who live in cities, nomads have always had a strong military mentality. As a result, the clans were more active and effective than their urban counterparts. They quickly become the lifeblood of the Seljuk border provinces in general and the Osmanic beylik in particular. Osman also enlisted the help of several Turkomen from the Paphlagonia area. These Turkomen were excellent warriors who were hungry for Jihad and Invasion. Each of them belonged to a Tariqah (a Sufi order) and was supervised by a sheikh who taught them the concept of Jihad and numerous Islamic precepts. However, another group of Turkomen did not have strong links to Islam; therefore, Osman committed them to numerous sheikhs and dervishes to receive good Islamic education and be satisfied with values that celebrate victories name of spreading Islam. Indeed, these sheikhs and dervishes were eager to promote the Turuq of the Khorasani Walis, and Osman's desire provided them with the opportunity. In terms of the governing structure, Osman was the first subject to the Chobanid Emir in Kastamonu, then the Seljuk Sultan via the Germiyanid Bey in Kütahya, who in turn was subordinate to the Mongol Ilkhan in Tabriz. The Seljuk Sultans had lost control over their local Emirs at this time, and the Mongol Ilkhan exercised his authority in Anatolia through his chosen Generals, requesting that every provincial governor, including Osman, give him men whenever he asked it. Imams used to pray for the direction of the Abbasid caliph in Egypt first, then the Mongol Ilkhan in Tabriz, the Seljuk Sultan in Konya, and finally the local Bey or Emir in the khuṭbah.

Osman I conquered the regions of Bilecik (Belokomis), Yenişehir (Melangeia), İnegöl  (Angelokomis), and Yarhisar (Köprühisar) until the end of the thirteenth century, as well as Byzantine fortresses in these territories. According to Shaw, Osman's first significant Invasions were when the Seljuks' power crumbled when he was able to take the castles of Kulucahisar and Eskişehir. Then he seized Yenişehir, the Ottoman capital, which was the first important city in his domains. Osman began moving his forces closer to Byzantine held territories in 1302, after soundly defeating a Byzantine force near Nicaea. The Byzantines increasingly departed the Anatolian countryside, alarmed by Osman's expanding power. The Byzantine authorities sought to halt the Ottoman expansion, but their attempts were ineffective and poorly coordinated.

Meanwhile, Osman spent the rest of his reign expanding his power in two directions: north following the Sakarya River's course and southwest towards the Sea of Marmara, accomplishing his goals by 1308. In the same year, his troops took part in the capture of Ephesus, a Byzantine city in the Aegean Sea, capturing the last Byzantine city on the coast, albeit it became part of the Emir of Aydin's realm. Osman's most recent campaign was against Bursa. Though Osman did not participate in the fight, the Ottoman victory at Bursa was crucial since the city acted as a staging ground against the Byzantines in Constantinople and a freshly decorated capital for Osman's son Orhan. According to Ottoman legend, Osman died shortly after the Invasion of Bursa, while some academics suggest that he died in 1324, after Orhan's succession.

Invasion of Karacahisar

Osman had to battle two fronts after establishing his beylik: one against the Byzantines and the other against the Turkomen beyliks that opposed his rule, particularly the Germiyanids. Osman focused on growing at the cost of the Byzantines, and the Invasion of the remaining Byzantine countries has been the principal Ottoman aim since then. According to some sources, Osman's first fight with the Byzantines was a retaliation for a loss he suffered in the spring of 683 or 684 AH / 1284 or 1285 CE, when the Byzantines, headed by Tekfur of Bursa, attacked him and his soldiers. It is unlikely that Osman was informed about the ambush by one of his spies. Nonetheless, he opted to fight the Byzantines, and he was beaten and forced to retreat, killing his nephew Koca Saruhan bey, son of Savcı Bey. Based on this, Osman sent a military army of three hundred soldiers to Kulacahisar, a stronghold located two leagues distant from İnegöl and within the purview of mount Uludağ, approximately 685 AH / 1286 CE. The Emir assaulted the fort at night and successfully conquered it, expanding his beylik northwards to the vicinity of Lake İznik. The Ottoman victory at Kulacahisar prompted the fort's governor, who refused to be a subordinate subject to a Muslim ruler, especially a border Emir, to ally with Karacahisar's governor, and the two men agreed to fight the Muslims to reclaim all Byzantine lands that had recently been lost. Thus, somewhere between Bilecik and İnegöl, the Ottomans and the Byzantines met again in combat when Osman's brother Savcı Bey and the Byzantine leader Pilatos were killed in intense fighting. The Ottomans were victorious in the battle. The Ottomans then marched into Karacahisar, where they purportedly transformed the town's church into a mosque for the first time.

Osman appointed a Qadi (magistrate) and a Subaşı (head of police) for the newly captured city. Historians disagreed on the exact date of the Invasion, although none occurred before 685 AH / 1286 CE or after 691 AH / 1291 CE. Osman used his new city as a staging area for his military expeditions against the Byzantines, and he had his name read at the Friday khuṭbah, which was the first public display of his power. However, Osman's most recent triumph was his most significant to that point. Seljuk Sultan Alâeddin Kayqubad III gave Osman the title of Ḥaḍrat ʻUthmān ghāzī marzubān 'Âli Jâh ʻUthmān Shāh (the honourable conqueror and border guardian Osman Shāh) in recognition of his achievements in the name of the Seljuks and Islam. The Sultan also gave Osman control over all of the areas he had captured, including the cities of Eskişehir and İnönü. In addition, the Seljuk Sultan issued an edict exempting Osman from all taxes. Osman also received many presents from the Sultan, demonstrating the Seljuk court's newfound prominence.

A golden battle banner, a mehter (war drum), a tuğ (a pole with circularly arranged horse tail hairs), a tassel, a gilded sword, a loose saddle, and 100,000 dirhams were among the presents. Osman's authority to be named in the Friday khubah in all places subject to him was also recognized in the mandate, as was his right to manufacture coins in his name. As a result, Osman became a Sultan, albeit only in name. When the drums announcing Sultan's Kayqubad's arrival were pounded, Osman rose in adoration and stayed thus till the music stopped. Since that day, whenever the drums have been played, Ottoman troops have enacted standing in worship for their Sultan.

Invasion of Bilecik, Yarhisar, and İnegöl: Following the capture of Karacahisar, Osman marched north towards the Sakarya River with his army. He attacked and sacked the forts of Göynük and Yenice Tarakl upon his arrival. Many believe Osman got a telegram from his Byzantine friend Köse Mihal around this period, alerting him of a covert plot being planned by the tekfurs of Bilecik and Yarhisar. They planned to assassinate Osman after inviting him to their children's wedding. Osman was unhappy that Bilecik's tekfur had deceived him. That is because he saw his connection with Bilecik as based on trust and good faith, mainly because his tribe was accustomed to leaving their possessions in this stronghold whenever they travelled between grazing regions, as previously stated. So Osman developed a strategy for escaping the trap and seizing control of the fortress. While most of Bilecik's residents were outside celebrating the wedding, he dispatched forty of his troops to transport some of the clan's goods to Bilecik. When his soldiers arrived at the fort, they rapidly overcame the fort's tiny garrison, and the Ottomans took control. The feast was then attended by Osman, who was followed by some Byzantine knights, who were attacked by his men afterwards.

Osman was successful in a brief combat, and the majority of the Byzantines were slaughtered. Following that, Osman rode up to Yarhisar and surprised it; a significant portion of the fort's garrison was killed, while the remainder were taken prisoner. Holophira, the tekfur's daughter, was also taken in this fight; she soon became Osman's daughter-in-law, marrying his son Orhan and changing her name to Nilüfer Hatun. Following that, Osman and many of his soldiers conquered all of the towns and villages surrounding İnegöl before laying siege to the fort and quickly capturing it. Osman had İnegöl's tekfur executed since he was renowned for harassing his Muslim neighbours, then set up a new garrison for the town and divided the loot among his soldiers.

Fall of the Seljuk Sultanate of Rûm and the Osmanic Beylik's independence: Following his several successes, Osman aimed to advance along two axes, attempting to isolate the Byzantine cities he sought to capture. He began by blocking the road going to İZnik from the east. He then marched westward towards Lopadion and Evrenos. After that, Osman circumnavigated Mount Uludağ from both the north and south, skirting Bursa's fortifications and uniting with his Muslim neighbours in the southeast. During this period, the Byzantine Empire was busy with battles with powerful Anatolian adversaries like the Germiyanids and coastal beyliks and repressing discontent and discord in Constantinople and the Balkans. Because the Empire was powerless to counter Osman's threats, he felt free to expand at the cost of the Byzantines, taking advantage of the present situation. At that time, the Seljuk Sultanate of Rûm was approaching the end of its reign. As a result, the Sultanate's hold over the Turkoman Beyliks eroded over time. After purging the Seljuk government of his predecessor's soldiers with great violence, Sultan Alâeddin Kayqubad III became highly unpopular. To preserve the peace in Anatolia, the Mongol Ilkhan Mahmud Ghazan summoned Kayqubad to come before him, and when he did so in 1302, he was killed and replaced with his predecessor Ghiyāth ad-Dīn Mas'ūd bin Kaykāwūs. According to another story, in 699 AH / 1300 CE, Mongol and Tatar forces attacked Asia Minor, killing Sultan Kayqubad in his capital Konya. Kaykāwūs was also supposed to have assassinated his opponent to reclaim the kingdom.

On the other hand, Kayqubad may have escaped and sought sanctuary at the Byzantine court, where he lived until his death, according to another account. Kaykāwūs' tenure was brief in both cases, lasting about 4 to 6 years. After he died in 1308 CE, the Seljuk Sultanate of Rûm was no longer recorded in historical sources, allowing the Turkoman beyliks to emerge as autonomous kingdoms.

After the Seljuk Sultanate of Rûm fell apart, Osman gained control of his domain and called himself Padişah Āl-ıʿOsmān  (sovereign of the house of Osman). Following that, Osman focused his eyes on capturing Anatolia's last Byzantine cities, towns, and castles. According to one story, after The Mongols slew sultan Alâeddin Kayqubad III, vizirs and prominent figures convened and determined that one of the local Emirs should have no progeny because the late Sultan had no progeny take his place, and they considered Osman to be a suitable choice. As a result, the leaders gave the Emir the post, and Osman accepted it and has been a Sultan ever since. The Sultanate of Rûm is believed to have fallen into disarray due to Kayqubad and Kaykāwūs' deaths, with many of its regular troops joining the forces of local Emirs, including Osman. This provided the latter with a lot of momentum and valuable combat experience, which he could use to prepare his army for future Invasions.

Combat of Bapheus

Osman sent instructions to all surviving Byzantine tekfurs in Anatolia shortly after gaining independence and establishing authority over all strongholds he captured, urging them to choose between adopting Islam, Ottoman rule, and paying jizyah or fighting. Some of these tekfurs converted to Islam, notably Osman's old acquaintance Köse Mihal, who became the Turkic leader's companion and would play a significant role in the Osmanic beylik's future expansions. In Ottoman history, his descendants were known as Mihaloğulları. Other governors recognized Osman's authority, but the others maintained their allegiance to the Byzantine Emperor. As a result, Osman began harassing their fortifications, including Bursa and Nicaea, which was besieged in 1301 CE. The Ottoman assaults also threatened starvation in Nicomedia since the Ottomans patrolled the area, preventing peasants from harvesting wheat. This prompted Bursa's tekfur, among others, to band together in an attempt to depose this new Islamic power. Emperor Michael IX conducted a campaign to the south of Magnesia in the spring of 1302 CE. Awed by his massive force, the Ottomans avoided a full-scale fight. The Emperor attempted to face the Ottomans, but his generals dissuaded him. The Ottomans were encouraged by this and repeated their incursions, thus isolating the Emperor in Magnesia. Soon after, the imperial army began to disband without fighting single combat, as local men withdrew to protect their homes. The Ottomans were regularly plundering, and the Alan mercenaries went to rejoin their relatives in Thrace. The Byzantine emperor was obliged to flee by water, and a tide of refugees followed him. To confront the danger to Nicomedia, Michael's father, Andronikos II, dispatched a Byzantine army of 2,000 soldiers (half of whom were freshly hired Alan mercenaries) to cross the Bosporus and relieve the city led by the mega hetaireiarches, Giorgios Mouzalon. The Byzantine response served as a warning to the Islamic border towns and villages. Locals flocked to support and stand with Osman after noticing his leadership and military prowess and his dedication to Islam to build a new Islamic state that would unify them and form an unbreakable wall against the Byzantines.

Several Byzantine deserters joined Osman as well; some of them were released prisoners of war who decided to unite with him owing to his proper treatment while in captivity, according to legend. The Ottomans also attracted several Islamic military brotherhoods. For example, since the Abbasid era, the Gazi Rûm's (Roman Raiders) have been stationed on the Byzantine Empire's frontiers, repelling Byzantine invasions on Muslim territory, acquiring valuable experience and expertise Byzantine plans and tactics. Another example is the Ḥajjian Rûms, a Muslim clerical fraternity tasked with educating local people and new converts on the fundamentals and other elements of Islam and helping the Mujahideen in warfare. The Byzantine and Ottoman forces finally met in the plain of Bapheus, between Nicomedia and Nicaea, on 1 Ḏū al-Ḥijjah 701 AH / 27 July 1302 CE. Under Osman's command, the Ottoman army totalled approximately 5,000 light cavalries, while the Byzantines numbered around 2,000 soldiers. The Byzantines' Alan contingent did not engage in the fight; thus, the Muslim cavalry charged at them quickly. The Byzantine line was breached due to the attack, forcing Giorgios Mouzalon to retreat into Nicomedia under cover of the Alan force. The Byzantines, in turn, effectively lost control of the countryside of Bithynia, withdrawing to their forts, which became isolated and eventually fell one by one. Bapheus was the foremost major victory for the nascent Osmanic Beylik, and it was of major significance for its future expansion: the Byzantines effectively lost control of the countryside of Bithynia, withdrawing to their forts, which became isolated and eventually fell one by one. The Byzantine loss also resulted in a massive migration of Christians from the region to the Empire's European portions, severely disrupting the region's demographic balance. The Ottomans reached the Aegean Sea beaches after their defeat at Magnesia, threatening Byzantium with a final loss of land in Asia Minor. The fight enabled the Ottomans to attain the features and qualities of an actual state, according to Turkish historian Halil İnalcık.

Byzantine-Mongol Convergence Attempt

Following his victory at Bapheus, Osman distributed the captured territory among his relatives and army commanders, establishing Islamic dominion and ending the Byzantine era in his new regions. He gifted his brother Gündüz bey - Eskişehir, his son Orhan - Karacahisar, Hasan Alp - Yarhisar, and Turgut Alp - İnegöl. Emperor Andronikos II was feeling the strain of Ottoman expansion at the time. The Emperor was alarmed by the dramatic demographic changes occurring in Anatolia, and he resolved to intervene. Nevertheless, having just been beaten, Andronikos II was unable to engage the Ottomans in open combat. As a result, conflicts erupted across the Balkans, adding salt to injury for the Byzantines. As a result, Andronikos II had little choice but to ally with the Persians, who controlled central and eastern Anatolia. To accomplish this, the Emperor wrote to Ilkhan Mahmud Ghazan, promising him a familial reconciliation through marriage and allying with the two Empires. Simultaneously, the Mongols were at odds with the Mamluks in Egypt and Syria, which strained relations with the Byzantines, especially as Ghazan prepared for a second invasion to Damascus and Palestine, following his first Invasion in 699 AH / 1299 CE, in which many civilians were massacred. Furthermore, the Mamluk army suffered a massive defeat at the Battle of Al-Aqsa. As a result, the Mamluks were preparing for a fight with the Mongols, hoping to erase the humiliation of their earlier defeat.

As a result, on 2 Ramadan 702 AH / 20 April 1303, CE, the Mongols and Mamluks fought a violent fight on the outskirts of Damascus known as the Battle of Shaqhab or Battle of Marj al-Saffar, in which the Mamluks triumphed decisively. This crushing loss took its toll on Ghazan, and it appears that it led to his health worsening even more, till he died at Qazvin on Sunday, 11 Shawwāl 703 AH / 17 May 1304 CE. Thus, any aspirations of a Byzantine-Mongol union were dashed, allowing the Ottomans to pursue Invasions.

Byzantine-Catalan Association

Following Ghazan's death, the Byzantine Emperor was obliged to look for alternative ways to deal with Ottoman expansion. As a result, he recruited a mercenary company headed by Roger de Flor from Catalonia. After the signing of the Peace of Caltabellotta between the Crown of Aragon and the French dynasty of the Angevins in 1302 CE, the mercenaries were out of work. The mercenaries landed at Constantinople in January 1303 CE, when the Emperor himself welcomed them. They were then lodged in the Blachernae neighbourhood. The Emperor arranged for Roger de Flor to marry his niece, Princess Maria Asanina, the 15-year-old daughter of Bulgarian Tsar Ivan Asen III and Irene Palaiologina. De Flor was given the title of Megas doux (Great Dux, for example - Commander of the Imperial Forces) and guaranteed a four-month salary for himself and his troops.

The Catalans quickly travelled into Asia Minor and battled the Karasids and Germiyanids, easily defeating them. They then determined to invade the Ottomans' marine territories. They marched to Philadelphia, which Osman had besieged, dominated by the Catalans and forced to withdraw his siege and escape. This victory demonstrated that if Byzantium had gathered adequate military forces and material capabilities, it would have been able to eradicate the Ottoman threat, but it lacked both. It was not long before the Catalans shifted their attention away from the Muslims and against the Byzantines themselves. The reason for this was that the local populace of Magnesia murdered the Catalan garrison and took their riches, which enraged Roger de Flor and drove him to march towards that city with the intention of exacting retribution. The mercenaries' raids terrified the Byzantines, who were obsessed with defending themselves. Roger de Flor was assassinated shortly after on the orders of the Emperor's son, Michael IX, who regarded the Catalan mercenaries' indiscipline as a rising threat, as did the people of Constantinople, who rose against them and slaughtered many of them. When the word reached the main Catalan force in Gallipoli, they embarked on a killing rampage of their own, killing all the Byzantines in the area. Soon after, the Byzantines and the Catalans were at odds, allowing Osman to continue with his Invasions.

Invasion of Yenişehir

Osman shifted his focus to his beylik's southern boundaries after securing his northern borders by reaching the Black and Marmara seas. As a result, he assaulted the Byzantine cities, villages, and strongholds that surrounded Yenişehir to capture it. First, Osman seized the fortress of Yvandhisar with a great expedition. Then he launched an attack on Yenişehir, which he easily conquered and established his temporary capital after reinforcing and upgrading its fortifications. Soon after, Osman began launching additional operations against the remaining Byzantine cities, capturing Lefke, Akhisar, Koçhisar, Yenicehisar, Marmarack, and Köprühisar, among others. In reality, as mentioned above, capturing the forts was part of Osman's plan to create a security belt around Yenişehir. Thus, he built a succession of front forts to keep invaders at bay.

Invasion of Bursa

With Yenişehir under his control, Osman turned his attention to major isolated cities, beginning with Bursa, unaware that this would be his final assault. He issued the order to begin construction on two forts that would watch over and encircle the city, and when they were finished, Osman provided strong garrisons to the forts. His soldiers were able to strengthen the blockade and prevent any supplies from reaching Bursa as a result. The Ottoman siege lasted between six and nine years due to the Ottomans' lack of siege engines and their lack of experience in capturing a major walled city. Several tekfurs recognized Osman's rule and became his subjects, with some adopting Islam in the process during the protracted siege. Soon after, Osman had Gout and could not join his soldiers in any more operations or see the Siege of Bursa; thus, he handed this tremendous job to his son Orhan while he retreated to his capital. Orhan kept the siege going without fighting, isolating Bursa from its fortifications by capturing Mudanya and cutting off the city's link to the sea. He also grabbed the city of Praenetos on İzmit's southern shore, renaming it Karamürsel after the Muslim leader who conquered it, "Karamürsel Bey." Beyce, which was considered Bursa's key since it overlooked it, was the last fort to fall, and it was renamed Orhaneli. Orhan strengthened the siege on Bursa to the point that the garrison was despondent. Soon after, the Byzantine emperor understood that the city would inevitably fall into Muslim hands; therefore, he took the painful choice to order his governor to depart the city. When Orhan arrived in Bursa on 2 Jumādā al-ʾŪlā 726 AH / 6 April 1326 CE, the people did not suffer any damage after acknowledging Ottoman rule and promising to pay jizyah. The garrison's commander, Saroz, surrendered to Orhan and swore loyalty to his father, Osman. In recognition of his bravery and patience throughout the protracted siege, he converted to Islam and was granted the title of "Bey." Some accounts claim that Osman died just before the city fell, while others claim that he survived long enough to hear of the triumph on his deathbed.

Osman's familial relationships are unknown due to a scarcity of sources concerning his life. According to certain fifteenth-century Ottoman historians, Osman was derived from the Kay branch of the Oghuz Turks, a claim that subsequently formed part of the official Ottoman genealogy and was finally entrenched in the Turkish Nationalist historical tradition writings of M. F. Köprülü. The claim to Kayı ancestry, on the other hand, does not occur in the earliest recorded Ottoman genealogy. As a result, many early Ottoman academics view it as a later invention intended to bolster dynasty legitimacy in the face of the Empire's Turkish opponents in Anatolia. Osman's ancestry was traced to Oghuz Khagan, the mythological progenitors of Western Turks, by Yazıcıoğlu Ali in the early 15th century, through his senior grandson of his senior son, giving Ottoman sultans supremacy among Turkish rulers. It is difficult for historians to tell what is true and what is mythical when it comes to the various legends the Ottomans spun about Osman and his adventures, and Ottoman sources do not always agree. According to legend, Osman disagreed with an uncle named Dündar early in his career. Osman desired to attack Bilecik's local Christian ruler, but Dündar objected, claiming that they already had enough enemies. So Osman shot and murdered his uncle with an arrow, mistaking this for a threat to his leadership position. This narrative comes in Neşri's work for the first time, yet it is absent from previous Ottoman historical writings. If this is accurate, it indicates that the murder of a family member was likely covered up to protect the Ottoman dynasty's founder's image. It might also signal a significant shift in the Ottomans' relationship with their neighbours, from generally peaceful accommodation to a more aggressive conquering strategy.

Osman is seen as a semi-holy figure in Ottoman history. Among the Turkoman tribes, it is known that the tribe or a portion of the tribe was called after its commander. The Kayi tribe became known as Osman implies that the tribe rose to prominence due to his outstanding leadership. According to Orientalist R. Rakhmanaliev, Osman's historical function was that of a tribal leader who was highly successful in unifying his people behind him. Historians of the past and present have praised Osman's accomplishments and personality as the creator of the state and dynasty. He is the founder of the state and the rulers' dynasty. Until the Ottoman Empire collapsed in the early twentieth century, the state's inhabitants were referred to as Ottomans. According to historian F. Uspensky, Osman used both force and guile to achieve his goals. According to historian and author Lord Kinross, Osman was a smart and patient king who was well-liked by his subjects and willing to serve him dutifully. He had a natural feeling of superiority, but he never attempted to impose himself by force. As a result, he was respected not just by those of comparable rank but also by those who outperformed him on the battlefield or in wisdom. Osman was "powerful enough to exploit masterful individuals," according to Herbert Gibbons. Osman for the Ottomans was the same as Romulus for the Romans, according to Cemal Kafadar.

According to accounts, Orhan raced back to Söğüt to notify his father of his tremendous triumph after hearing of the fall of Bursa. He was immediately summoned to Osman, who was on his deathbed, as he arrived. Osman died of natural causes not long after hearing the news. Even though Orhan was not Osman's firstborn, Osman was able to name him as his successor. Despite this, the late Emir thought Orhan was more suited to govern than his elder half-brother Alâeddin, who was more quiet and religious than Orhan. The actual reason for Osman's death is unknown; however, he was known to have suffered from Gout for several years, which may have contributed to his death. This is supported by what Aşıkpaşazade said of Osman's late time of life in Tevarih-i Âl-i Osman, when he said, "Osman had a bad foot from which he endured great agony." When talking about Sultan Mehmed the Conqueror's death, Aşıkpaşazade used a similar expression: "The cause of his death was the problem in his feet." Many sultans of the Ottoman empire suffered from Gout, which is now recognized as a hereditary illness. The precise date of Osman's death is unknown. He is believed to have died at 70 on 21 Ramaḍān 726 AH / 21 August 1326 CE. Osman died around 1320, according to the 15th-century Ottoman historian Rouhi Çelebi, who wrote down the Ottoman Empire's history until 1481 CE. However, another Ottoman historian, Uruç adiloğlu, who lived between Sultans Mehmed the Conqueror and Bayezid II until 1502 CE, claims that Osman died in 1327 CE. Despite the lack of records bearing Osman's name after 1320 CE, there exists documentation proving Orhan's accession to the throne in 1324 CE, according to contemporary Turkish historian Necdet Sakaoğlu [tr].

Osman's death might have occurred in the preceding year, based on this. It is also certain that Osman died three or four months after his father-in-law, Sheikh Edebali, and two months after his wife, Malhun Hatun, because Osman is known to have buried the two in Bilecik. Orhan ordered Osman's remains to be transported to Bursa, his new capital when he died. As a result, Osman's body was put to rest there. His tomb may still be seen in the Tophane neighbourhood today. The rationale for the move was owing to a will Osman left his son during the early years of the siege of Bursa: "My Son, bury me beneath the silver dome in Bursa when I die." Osman's present tomb, on the other hand, comes from the reign of Sultan Abdü'l-ʻAzīz (1861–1876 CE), since the original tomb was totally damaged in a major earthquake that devastated the region in 1855 CE, and the Sultan as mentioned above, reconstructed it.

Sultan Abdü'l-Ḥamīd II (1876–1909 CE) also built a shrine in Söğüt, where Osman was temporarily interred before being transferred to Bursa. According to some historians, Osman left a written will to his son Orhan, directing him to continue Invasions and Jihad against the Byzantines, following the principles of Islam, accompanying the Ulamā, changing his parish and devote himself to spreading the message of Islam.

The Ottoman dynasty is said to have been founded by Osman. He established an imperial line that would eventually include thirty-five sultans who reigned over one of the world's greatest and most powerful empires. The Ottoman Empire lasted until 1918 CE when it fell victim to defeat in the First World War and the other Central Powers. Osman is commonly referred to be the first of the Ottoman Sultans, even though he was never named "Sultan" during his lifetime and was instead referred to as "Bey" or "Emir." Osman was granted the titles Muiuddin and Fakhruddin, according to a Persian endowment dated from 1324 CE. After the royal Ottoman family was driven from Turkey in 1924 CE, shortly after Mustafa Kemal Atatürk declared the Republic, Osman's descendants are now spread throughout various American, European, and Arab nations. After the Turkish government allowed females to return to Turkey in 1951 CE, some family members eventually returned. Male descendants, on the other hand, had to wait until 1973 CE to return to Turkey. Others stayed in the nations where their forefathers had sought shelter, including England, France, the United States, Egypt, and Saudi Arabia. The Osmanoğlu family is named after Osman's descendants.

Starting with Sultan Murad II, the Weapon of Osman was a critical state sword used at the Ottoman Sultans' coronation ceremonies. When Osman's father-in-law, Sheik Edebali, girt him with the Islamic sword, the practice began. The girding of Osman's sword was a crucial rite that took place within two weeks of a sultan's throne ascension. It was held at the capital Constantinople's tomb complex at Eyüp, on the Golden Horn canal. The fact that a sultan's enthronement symbol was a sword was highly symbolic. It indicated that the office with which he was invested was first and foremost a warrior's office. The Sharif of Konya, a Mevlevi dervish, brought to Constantinople for the occasion, girded the Sword of Osman on the new ruler.

Osman has appeared in the Turkish television series Kuruluş "Osmancık" (1988), which was based on a novel of the same name, as well as Diriliş: Ertuğrul and Kuruluş: Osman.