Overview of Mongol Empire

Through the 13th and 14th centuries, the Mongol Empire was the world's biggest contiguous land empire, second only to the British Empire in relationships of landmass. The Mongol Empire, which began in Mongolia in East Asia and ultimately pushed from Eastern Europe and portions of Central Europe to the Sea of Japan, spreading northward into portions of the Arctic, eastward and southward interested in the Indian subcontinent, Continental Southeast Asia, and the Iranian Plateau, and westward as far as the Levant, the Carpathian Mountains, and the Northern European borders. The Mongol Empire arose from the confederation of many nomadic tribes in the Mongol heartland, led by Genghis Khan, who was proclaimed king of all Mongols by a council in 1206. Under his and his descendants' control, the Empire flourished fast, sending invading troops in every direction. In an enforced Pax Mongolica, the huge transcontinental Empire united the East with the West, the Pacific with the Mediterranean, allowing the spread and exchange of trade, technologies, commodities, and philosophies.

The kingdom began to split due to succession disputes between Genghis Khan's grandchildren, who argued over whether the royal line should be descended from his son and first heir, Ogedei, or one of his other sons, Tolui Chagatai, or Jochi. After a deadly cleansing of Ogedeid and Chagatayid groups, the Toluids triumphed, but disagreements arose among Tolui's successors. The disagreement over whether the Mongol Empire would become a passive, cosmopolitan empire or remain true to the Mongol nomadic and steppe-based lifestyle was a major cause of the split. Following Mongke  Khan's death, opposing kurultai councils elected two successors, Ariq Boke and Kublai Khan. They fought each other in the Toluid Civil War and faced challenges from the descendants of other Genghis sons. Kublai succeeded in gaining power, but civil war broke out as he failed to control the Chagatayid and Ogedeid families. Occasionally, during Genghis and Ogedei, the Mongols were defeated when a less capable leader was given command. Around 1215–1217, the Siberian Tumeds beat Borokhula's Mongol armies; in 1221, Jalal al-Din defeated Shigi-Qutugu at Parwan's Battle 1230, the Jin generals Heda and Pu'a defeated Dolqolqu. The Mongols returned with a considerably bigger army, headed by their best generals, and won every occasion. Due to a confluence of factors, including Mongke  Khan's death in 1259, the Toluid Civil War between Ariq Boke and Kublai Khan, and Berke Khan of the Golden Horde attacking Hulagu Khan in Persia, the Mongols did not return to revenge a defeat until the Battle of Ain Jalut in Galilee in 1260. After a decisive victory in the Battle of Wadi al-Khaznadar in 1299, the Mongols launched numerous more attacks of the Levant, briefly occupying it and raiding as far as Gaza. Still, they left due to various geopolitical causes.

The Mongol Empire had wrecked up into four separate khanates or empires by the time of Kublai's death in 1294, each pursuing its benefits and purposes: the Golden Horde khanate in the northwestern, the Chagatai Khanate in Central Asia, the Ilkhanate in the southwest, and the Yuan reign in the East, based in modern-day Beijing. The three western khanates briefly recognised the Yuan dynasty's nominal suzerainty in 1304, but the Han Chinese Ming dynasty acquired the Mongol capital in 1368. The Yuan's Genghisid emperors returned to Mongolia's homeland and established the Northern Yuan dynasty there. Between 1335 and 1353, the Ilkhanate fell apart. By the end of the 15th century, the Golden Horde had split into warring khanates. It was conquered and expelled from Russia by the Grand Duchy of Moscow in 1480, while the Chagatai Khanate persisted until 1687 in various forms.

In Mongol, the Mongol Empire was known as yeke Mongol ulus nation of the great Mongols, or the big Mongol nation. Kublai Khan's control was limited to the eastern section of the Empire, centered on China, after the succession conflict between him and his brother Ariq Boke in 1260-1264. On December 18, 1271, Kublai issued an imperial proclamation naming his kingdom Great Yuan (Dai Yuan) and establishing the Yuan dynasty. Thus, the full Mongolian name is Dai Yuan Yehe Monggul Ulus, according to certain sources.

Pre-empire Background

Since the 10th century, the Liao dynasty has ruled over the region around Mongolia, Manchuria, and parts of North China. The Jurchen-founded Jin dynasty defeated the Liao dynasty in 1125 and attempted to control former Liao territory in Mongolia. In the 1130s, the Golden Kings of the Jin dynasty successfully repelled the Khamag Mongol confederation, led by Khabul Khan, Genghis Khan's great-grandfather. Five great tribal confederations dominated the Mongolian Plateau: the Keraites, Khamag Mongols, Naimans, Mergids, and Tatars. The Jin emperors used a divide-and-rule strategy, encouraging tribal feuds, particularly between the Tatars and the Mongols, to keep the nomadic tribes focused on their battles and away from Jin. Ambaghai Khan, Khabul's successor, was deceived by the Tatars, turned to the Jurchen, and executed. In 1143, the Mongols replied by assaulting the frontier, which resulted in a failed Jurchen counter-offensive. Jin adjusted their policy slightly in 1147, signing a peace deal with the Mongols and withdrawing from many forts. To revenge the murder of their late Khan, the Mongols renewed attacks on the Tatars, beginning a long era of active conflicts. In 1161, the Mongols were crushed by Jin and Tatar armies. The normally cold, arid steppes of Central Asia had their mildest, wettest circumstances in more than a millennium during the emergence of the Mongol Empire in the 13th century. This has resulted in rapid growth in the number of war horses and other livestock, bolstering the Mongol military might greatly.

The Upsurge of Genghis Khan

Genghis Khan was the son of a Mongol lord and was known as Temujin during his boyhood. Working with Toghrul Khan of the Kerait helped him rise quickly as a young man. Kurtait, the most powerful Mongol chieftain of the period, was given the Chinese title "Wang," which translates to "King." Temujin declared war against Kurtait. Temujin took the moniker Genghis Khan after defeating Wang Khan. After that, Khan expanded his Mongol state to include himself and his kin. The term Mongol evolved to apply to all Mongolic-speaking tribes under Genghis Khan's rule. His father's buddy, Khereid chieftain Toghrul, Temujin's boyhood and (blood brother), Jamukha of the Jadran clan were his most formidable allies. Temujin destroyed the Merkit tribe with their support, liberated his wife Borte, and defeated the Naimans and Tatars. Temujin outlawed plundering of his opponents without permission, and instead of distributing all of the treasures to the nobles, he decided to share them with his warriors and their families. These practices caused him to clash with his uncles, also rightful heirs to the throne; they saw Temujin as an obnoxious usurper rather than a leader. This discontent spread among his generals and acquaintances, and those Mongols who had previously been supporters turned against him.

Nevertheless, Temujin and his remaining armies won the war, defeating the last enemy tribes between 1203 and 1205 and bringing them under his control. At a Kurultai (general assembly/council) in 1206, Temujin was crowned as the khagan (Emperor) of the Yekhe Mongol Ulus (Great Mongol State). He took the title of Genghis Khan (universal leader) rather than one of the ancient tribal titles like Gur Khan or Tayang Khan, and so the Mongol Empire was born.

Primary Organisation

Genghis Khan reorganised his army in several novel ways, including splitting it into decimal divisions of arbans (10 troops), zuuns (100), Mingghans (1000), and tumens (2000). (10,000). The imperial guard, the Kheshig, was established and was divided into day (khorchin torghuds) and night (khevtuul) guards. Even though many hailed from low-ranking clans, Genghis honoured those loyal to him by placing them in high positions, such as chiefs of army units and houses. Those allotted to his family members were scant compared to the units he provided to his faithful acquaintances. He established a new code of law for the Empire, Ikh Zasag or Yassa, which he later expanded to incorporate much of the nomads' daily lives and political affairs. He made it illegal to sell women, steal, fight among Mongols, and hunt animals during the breeding season. He named his adopted brother Shigi-Khuthugh as supreme judge (jarughachi) and tasked him with keeping the Empire's archives. Genghis also decreed religious freedom and encouraged domestic and foreign trade, in addition to the family, food, and army rules. He exempted the clergy and the needy from paying taxes. He also promoted literacy by adopting the Uyghur alphabet, eventually becoming the Empire's Uyghur-Mongolian script, instructing his sons through the Uyghur Tatatunga, who had previously served the Khan of Naimans.

Death of Genghis Khan and Development under Ogedei (1227–1241)

The Mongol Empire spanned from the Pacific Ocean to the Caspian Sea when Genghis Khan died on August 18, 1227, an empire twice the size of the Roman Empire or the Muslim Caliphate at their peak. Genghis designated his charismatic third son, Ogedei, as his heir. Genghis Khan is said to have been buried at a secret place, according to Mongol legend. Ogedei's formal election at the kurultai in 1229 held the regency by Ogedei's younger brother Tolui. Ogedei's early operations sent troops into the Kipchak-controlled steppes to conquer the Bashkirs, Bulgars, and other tribes. Ogedei's army crushed the Eastern Xia government and the Water Tatars in the East, restoring Mongol rule in Manchuria. The great Khan personally commanded his troops in a campaign against China's Jin kingdom in 1230. During the siege of Kaifeng in 1232, Ogedei's general Subutai conquered Emperor Wanyan Shouxu's capital. When the Mongols conquered Caizhou, where Wanyan Shouxu had fled, the Jin kingdom fell apart in 1234. The invasion of southern China was launched in 1234 by three armies led by Ogedei's sons Kochu and Koten and the Tangut leader Chagan. The Mongols defeated Jin in 1234, with the Song dynasty's help. To oppose Jin, many Han Chinese and Khitan defected to the Mongols. Shi Tianze, Liu Heima (Liu Ni), and the Khitan Xiao Zhala, three Han Chinese leaders, defected and took the Mongol army's three Tumens. Ogodei Khan was served by Liu Heima and Shi Tianze. For the Mongols, Liu Heima and Shi Tianxiang led troops against Western Xia. Each Tumen had 10,000 troops, and there were four Han Tumens and three Khitan Tumens. The Yuan dynasty developed two armies: a Han army made up of Jin defectors, and a Newly Submitted Army made up of ex-Song warriors. In the West, Ogedei's general Chormaqan defeated Jalal ad-Din Mingburnu, the Khwarizmian Empire's last monarch. Southern Persia's tiny kingdoms willingly accepted Mongol dominance. Several Mongolian campaigns into Goryeo Korea in East Asia, but Ogedei's attempt to capture the Korean Peninsula failed. Gojong, Goryeo's king, submitted but later revolted and executed Mongol darughachis (overseers); he then relocated his royal palace from Gaeseong to Ganghwa Island.

Post-Ogedei Power Struggles (1241–1251)

Following the death of the Great Khan Ogedei in 1241, Ogedei's widow Toregene assumed control of the Empire before the next kurultai. She persecuted her husband's Khitan and Muslim officials and promoted her loyalists to top posts. She supported religion and education by building palaces, cathedrals, and social infrastructure on an imperial scale. She was successful in persuading the majority of Mongol aristocrats to support Ogedei's son Guyuk. However, the Golden Horde's monarch, Batu, refused to attend the kurultai, stating that he was ill and that the Mongolian environment was too severe for him. The ensuing standoff lasted more than four years, further destabilising the Empire's unity. Guyuk travelled to the Karakorum to secure his position after Genghis Khan's youngest brother Temuge sought to usurp the throne. Toregene summoned a kurultai in 1246, and Batu agreed to send his brothers and generals. Guyuk was sick and alcoholic at the time, but his conquests in Manchuria and Europe had given him the status of a great khan. He was duly elected at a ceremony attended by Mongols and foreign dignitaries from both within and outside the Empire, including vassal chiefs, representatives from Rome, and others who came to pay their respects and conduct diplomacy at the kurultai. Guyuk attempted to decrease corruption, declaring that he would follow his father Ogedei's ideas rather than Toregene's. Except for governor Arghun, the Elder, he punished Toregene's adherents. To emphasise his newly given powers, he supplanted young Qara Hulegu, the Khan of the Chagatai Khanate, with his beloved relative Yesu Mongke. He reinstalled his father's officials and surrounded himself with Uyghur, Naiman, and Central Asian officials, preferring Han Chinese commanders who had assisted his father in conquering Northern China. He kept military operations in Korea going, moved into Song China in the south and Iraq in the West, and ordered a census of the entire Empire. Guyuk also split the Sultanate of Rum between Izz-ad-Din Kaykawus and Rukn ad-Din Kilij Arslan, despite Kaykawus' objections. Guyuk's election was not well received throughout the Empire. Guyuk was enraged when the Hashshashins, former Mongol allies whose Grand Master Hasan Jalalud-Din had offered Genghis Khan his submission in 1221, refused. Instead, in Persia, he assassinated the Mongol generals. Guyuk named his best friend's father, Eljigidei as the main commander of Persia's armies, tasked with weakening Nizari Ismaili strongholds and conquering the Abbasids in the Islamic world's heartland, Iran and Iraq.

Rule of Mongke  Khan (1251–1259)

The gathering crowd declared Mongke great khan of the Mongol Empire when Mongke's mother Sorghaghtani and cousin Berke organised a second kurultai in July 1, 1251. This represented a significant transition in the Empire's leadership, passing authority from Genghis' son Ogedei's descendants to Genghis' son Tolui's descendants. Several Ogedeid and Chagataid princes, including Mongke's cousin Kadan and the ousted Khan Qara Hulegu, acknowledged Mongke's decision. Still, one of the other legal heirs, Ogedei's grandson Shiremun, attempted to remove Mongke. Shiremun sent his soldiers toward the emperor's mobile palace to launch an armed attack, but his falconer informed Mongke of the plan. Mongke ordered a probe into the scheme, which resulted in a flurry of significant trials across the Empire. With estimates varying from 77 to 300, many members of the Mongol aristocracy were found guilty and executed, while princes of Genghis' royal line were frequently exiled rather than executed. Mongke seized the Ogedeid and Chagatai families' domains and divided the Empire's western half with Batu Khan. Mongke decreed a general amnesty for detainees and captives following the brutal purge, but the power of the great Khan's throne remained firmly in the hands of Tolui's successors.

Disagreement

Hulagu, Mongke's brother, halted his successful military march into Syria, retreating the majority of his men to Mughan and left only a small group under Kitbuqa's command. Recognising that the Mongols were the greater threat, the rival groups in the region, the Christian Crusaders and Muslim Mamluks, took advantage of the Mongol army's weakened state and entered into an uncommon passive truce with each other. The Mamluks advanced from Egypt in 1260, with permission to camp and replenish near the Christian stronghold of Acre, and engaged Kitbuqa's soldiers at the Battle of Ain Jalut, just north of Galilee. Kitbuqa was executed after the Mongols were defeated. This decisive fight established the western boundary of Mongol expansion in the Middle East, and the Mongols were never able to make significant military advances beyond Syria again. There were battles between Kublai's soldiers and his brother Ariqboke's, including forces loyal to Mongke's former regime. Kublai's troops dispatched Ariqboke's allies with ease and seized control of the civil administration in southern Mongolia. The Chagataids, their cousins, presented them with new obstacles. Kublai appointed Abishka, a Chagataid prince who was devoted to him, to rule Chagatai's Empire. Ariqboke, on the other hand, caught and executed Abishka instead of crowning his own man Alghu. Kublai's new administration cut off food supplies to Ariqboke in Mongolia, triggering a famine. Kublai soon conquered the Karakorum, but Ariqboke rallied and reclaimed the capital in 1261. The Mongols pursued the final conquest of the Song dynasty in South China after the defeat of Xiangyang in 1273. Kublai Khan called the new Mongol authority in China the Yuan dynasty in 1271, attempting to sinicise his image as Emperor of China to gain control of the Chinese people. Kublai Khan established his headquarters in Khanbaliq, which would subsequently become the present city of Beijing. Many Mongols criticised his decision to create a capital there, accusing him of being excessively influenced by Chinese culture. The Mongol operations against China were eventually successful. The Chinese Song imperial family submitted to the Yuan in 1276, making the Mongols the first non-Chinese people to capture the entire country. Kublai built a vast empire from his base, establishing an academy, offices, trading ports and canals, and supporting the arts and sciences. During his reign, Mongol archives show that he established 20,166 public schools.

Crumbling into Opposing Entities

In the late 1200s, the Mongol Empire saw significant upheavals. Kublai Khan died in 1294 after conquering all of China and establishing the Yuan dynasty. Temur Khan, Kublai's grandson, succeeded him and continued Kublai's policies. At the same time, the Toluid Civil War, as well as the Berke–Hulagu war and the subsequent Kaidu–Kublai war, severely weakened the great Khan's authority over the Mongol Empire, resulting in the division of the Empire into autonomous khanates, the Yuan dynasty, and the three western khanates: the Golden Horde, the Chagatai Khanate, and the Ilkhanate. Only the Ilkhanate remained faithful to the Yuan court. Still, it was embroiled in its power struggle, partly due to a confrontation with the Empire's rising Islamic factions in the southwest. Following Kaidu's death, Chatagai ruler Duwa proposed peace and persuaded the Ogedeids to submit to Temur Khan. In 1304, all of the khanates signed a peace treaty acknowledging the rule of Yuan emperor Temur. This established the Yuan dynasty's formal dominance over the western khanates, which would last several decades. The new Khagans' power was built on weaker foundations than the previous Khagans', and each of the four khanates continued to flourish and function as autonomous states. After nearly a century of conquest and civil conflict, the Pax Mongolica brought relative peace to Asia and Europe, and international trade and cultural contacts flourished. Communication between China's Yuan dynasty and Persia's Ilkhanate boosted trade and commerce between the East and West. Yuan royal textile patterns embellish Armenian decorations on the other side of the Empire; trees and crops were transplanted across the Empire, and technological advancements spread from Mongol dominions to the West. While the four khanates interacted with one another long into the 14th century, they did so as sovereign entities, never pooling their resources in a coordinated military effort.

Relict States of the Mongol Empire

Mongol power collapsed after Ilkhan Abu Said Bahatur in 1335, and Persia descended into political chaos. The Ilkhanate was divided between the Suldus, the Jalayir, the Qasarid Togha Temur, and Persian warlords after his successor was slain by an Oirat governor a year later. The Georgians took advantage of the confusion to drive the Mongols out of their lands, and in 1336, the Uyghur general Eretna created an independent empire in Anatolia. Following the demise of their Mongol masters, the Armenian Kingdom of Cilicia, a faithful vassal, faced increasing Mamluk threats and was eventually invaded in 1375. Mongol monarchs in China and the Chagatai Khanate were likewise in upheaval due to the disintegration of the Ilkhanate in Persia. The Black Death, which began in the Mongol dominions and swept Europe, contributed to the chaos. All of the khanates were devastated by disease, which severed trading relations and killed millions. In the 14th century, the plague may have killed 50 million people in Europe alone. As the Mongols' control waned, anarchy spread across the Empire as non-Mongol rulers increased their power. Between 1342 and 1369, the Golden Horde lost all of its western dominions, including modern-day Belarus and Ukraine, to Poland and Lithuania. From 1331 until 1343, Muslim and non-Muslim princes in the Chagatai Khanate fought each other. The Chagatai Khanate fell apart when non-Genghisid warriors established their puppet khans in Transoxiana and Moghulistan. Janibeg Khan reasserted Jochid dominance over the Chaghataids for a short time.         

The amount of Mongol forces mobilised is a matter of contention among scholars, but it was at least 105,000 in 1206. The Mongol military structure was based on the decimal system and was basic but effective. The army was made up of ten-man squads of arbans, zuuns, Mingghans, and tumens. The Mongols were known for their horse archers, but lance-wielding troops were just as capable, and the Mongols attracted other military experts from the lands they conquered. The Mongols could lay siege to fortified strongholds employing experienced Chinese engineers and a bombardier corps expert at creating trebuchets, catapults, and other machines, sometimes building machinery on the spot using available local resources. The Mongol Empire's armies were well-trained, organised, and equipped for mobility and speed. Mongol soldiers were less well-armoured than many of the armies they encountered, but they made up for it in agility. Typically, each Mongol fighter would travel with many horses, allowing him to switch to a new mount as needed rapidly. Furthermore, Mongol army soldiers operated independently of supply lines, significantly speeding up army movement. The leaders of these armies were able to communicate with one another because of couriers' skilful employment.

According to Juvayni, discipline was instilled during a nerge (traditional hunt). These hunts were different from hunts in other cultures because they resembled small unit actions. Mongol armies would form a line, encircle an entire territory, and then herd all animals in that area together. The goal was to ensure that none of the animals escaped and that they were all slaughtered. The Mongols also benefitted from travelling long distances even in abnormally cold winters; for example, frozen rivers led them like highways to enormous urban centres on their banks. During the Battle of Mohi, the Mongols crossed the river Sajo in spring flood conditions with thirty thousand cavalry warriors in a single night to defeat the Hungarian king Bela IV. Similarly, a fleet of barges was utilised to prevent the Muslim Khwarezmshah from fleeing across the river during the attack.

The Mongols, who were known for their land force strength, rarely deployed naval might. They used seapower to conquer the Song dynasty of China in the 1260s and 1270s. However, their attempts to organise seaborne wars against Japan were unsuccessful. Their wars in the Eastern Mediterranean were virtually entirely on land, with the waters controlled by Crusader and Mamluk forces. Before any military campaign, thorough planning, surveillance, and the gathering of sensitive information about enemy areas and forces were conducted. The Mongol forces' success, organisation, and mobility allowed them to fight on multiple fronts simultaneously. Conscription into the army was open to all adult males up to the age of 60, and it was regarded as a source of honour in their tribal warrior heritage.

Commandment and Governance

The Mongol Empire was ruled by Genghis Khan's Yassa system of law, which meant "order." One of the canons of this code was that individuals in positions of power faced many of the same difficulties as the common person. It also enforced harsh penalties, such as the death penalty for a mounted soldier who failed to pick up something dropped from the horse in front of him. Rape and, to a lesser extent, murder were also sanctioned. Any opposition to Mongol dominance was greeted with a savage retaliation. If cities disobeyed Mongol commands, they were demolished and their population killed. Chiefs and generals were chosen based on merit under Yassa. The Mongol leaders gathered with the great Khan to discuss domestic and international policies in a non-democratic, parliamentary-style central assembly known as kurultai. Kurultais were also held for the appointment of each new great Khan. In addition, Genghis Khan established a national seal, pushed Mongolians to utilise a written alphabet, and freed teachers, attorneys, and artists from paying taxes.

Religions

From Buddhism to Christianity, Manichaeism to Islam, nearly every religion had attracted Mongol followers at the time of Genghis Khan. Although he was a shamanist, Genghis Khan established an organisation to offer complete religious freedom to avoid conflict. All religious leaders were excused from taxation and public duty throughout his regime. Because of the nomadic lifestyle, there were few official places of worship at first. However, several building projects were undertaken in the Mongol capital during Ogedei (1186 until 1241).

Along with palaces, Ogedei constructed temples for Buddhists, Muslims, Christians, and Taoists. Shamanism, Tengrism, and Buddhism were the prominent religions, while Ogedei's wife was a Nestorian Christian. The Chinese-Mongolian Yuan dynasty in the East (originally the great Khan's dominion) eventually absorbed Buddhism and Shamanism, while the three Western khanates eventually adopted Islam.

Arts and Literature

The Secret History of the Mongols, written for the royal family sometime after Genghis Khan died in 1227, is Mongolian's oldest extant literary work. It is the most important local narrative of Genghis Khan's life and lineage, encompassing everything from his birth and youth to the founding of the Mongol Empire and his son Ogedei's rule. The Jami' al-tawarikh, or Universal History, is another imperial masterpiece. The Ilkhan Abaqa Khan commissioned it in the early 14th century to chronicle the entire world's history and establish the Mongols' cultural heritage. As a crude type of correction fluid, Mongol scribes in the 14th century employed a mixture of resin and vegetable pigments; this is possibly its first recorded use. Again, the Mongols enjoyed the visual arts, albeit their preference for portraiture was limited to images of their horses rather than people.

Science

Because of the Khans' sponsorship, the Mongol Empire experienced great advances in science. The Mongols' prowess as world conquerors, according to Roger Bacon, was due mostly to their devotion to mathematics. One aspect of study in which the Khans were particularly interested was astronomy. According to Yuanshi, Ogedei Khan ordered the repair of Zhongdu's armillary sphere in 1233 and 1236 and the revision and acceptance of the Damingli calendar in 1234. Around 1236, he built a Confucian temple for Yelu Chucai at the Karakorum, where Yelu Chucai developed and regulated a Chinese-style calendar. Rashid al-Din credited Mongke Khan with solving some difficult Euclidean geometry problems on his own, and he wrote to his brother Hulagu Khan to send him the astronomer Tusi. Unfortunately, Mongke Khan's wish for Tusi to build an observatory in the Karakorum was never fulfilled because the Khan died while on a campaign in southern China. Instead, Hulagu Khan offered Tusi a grant in 1259 to erect the Maragheh Observatory in Persia and instructed him to prepare astronomical tables for him in 12 years, despite Tusi's request for 30. Tusi completed the Ilkhanic Tables in 12 years, published a revised copy of Euclid's Elements, and introduced the Tusi couple, an ingenious mathematical device. Tusi saved around 400,000 books from the siege of Baghdad and other towns at the Maragheh Observatory. Hulagu Khan also sent Chinese astronomers to work there. Kublai Khan built several big observatories in China, and his libraries featured Muslim mathematicians' Wu-hu-lie-ti. In Mongol-ruled China, renowned mathematicians were Zhu Shijie and Guo Shoujing. Hu Sihui, a Mongol physician, wrote a medical book in 1330 that stressed the significance of a healthy diet.

The Mail System

For its period, the Mongol Empire had a sophisticated and efficient mail system known as the Yam by scholars. Throughout the Empire, richly equipped and well-guarded relay posts known as ortoosetup. A messenger would normally go 40 kilometres from one station to the next, either obtaining a new, rested horse or handing the letter to the next rider to guarantee the quickest delivery possible. The Mongol riders routinely traversed 200 kilometres each day, breaking the record set 600 years later by the Pony Express. Households were connected to the relay stations so that they could be serviced. Anyone with a paiza could stop for remounts and specific rations, but individuals with military IDs could use the Yam even if they didn't have a paiza. The technique was utilised by many merchants, messengers, and travellers from China, the Middle East, and Europe. Thanks to the Yam, news of the great Khan's death in the Karakorum reached the Mongol forces under Batu Khan in Central Europe within 4–6 weeks. Genghis and his successor Ogedei constructed a vast highway network, including one that cut over the Altai Mountains. Following his enthronement, Ogedei ordered the Chagatai Khanate and the Golden Horde to link up routes in the western sections of the Mongol Empire. The founder of the Yuan dynasty, Kublai Khan, constructed special relays for elite officials and regular relays with hostels. During Kublai's rule, the Yuan communication system included 1,400 mail stations, 50,000 horses, 8,400 oxen, 6,700 mules, 4,000 carts, and 6,000 boats. The Mongols still utilised dogsled relays for the Yam in Manchuria and southern Siberia. Ghazan rebuilt the Middle East's deteriorating relay system on a limited basis in the Ilkhanate. He built some hostels and made it such that only imperial envoys were paid a stipend. The Golden Horde's Jochids used a special Yam tax to fund their relay system.

The Mongols were known for their support of merchants and trade. Even before uniting the Mongols, Genghis Khan supported foreign traders early in his career. Merchants offered information about adjacent civilizations, acted as Mongol diplomats and official dealers, and were necessary for many items because the Mongols produced little of their own. In an ortoq (commercial partner) arrangement, the Mongol government and elites provided capital to merchants and dispatched them far away. The contractual features of a Mongol-ortoq partnership were similar to those of qirad and commenda arrangements in Mongol times. Still, Mongol investors were not restricted from using uncoined precious metals and tradable goods for partnership investments and primarily financed money-lending and trade activities.

Furthermore, Mongol aristocrats forged trading alliances with Italian merchants, notably Marco Polo's family. As the Empire flourished, any merchants or ambassadors travelling through Mongol domains with valid documents and authorization gained security and asylum. Well-used and reasonably well-maintained highways connected lands from the Mediterranean basin to China, considerably expanding overland trade and creating amazing accounts of those who went along the Silk Road. Marco Polo, a Western traveler, travelled east along the Silk Road. Rabban Bar Sauma, a Chinese Mongol monk, made a similarly epic voyage, travelling from Khanbaliq (Beijing) to Europe. European missionaries, such as William of Rubruck, went to the Mongol court to persuade believers to join their cause or served as papal envoys to communicate with Mongol monarchs in an attempt to create a Franco-Mongol alliance. It was, nevertheless, uncommon for someone to travel the entire length of the Silk Road. Instead, traders transferred items like a bucket brigade, trading goods from one middleman to the next, from China to the West; goods transported over such long distances commanded exorbitant rates. Following Genghis, Ogedei and Guyuk continued to prosper in the merchant partner industry. Merchants delivered clothing, food, information, and other supplies to the imperial palaces. In exchange, the great khans granted tax exemptions and enabled merchants to use the Mongol Empire's official relay stations. In China, Russia, and Iran, merchants also worked as tax collectors. If bandits attacked the merchants, the imperial treasury was used to compensate them.

The policies of the Great Khan Mongke shifted. He attempted to limit abuses by sending imperial investigators to supervise ortoq enterprises due to money laundering and overtaxing. He ordered that all merchants pay commercial and property taxes, and he cancelled all drafts drawn on merchants by high-ranking Mongol elites. During the Yuan dynasty, this policy was maintained. The demise of the Mongol Empire in the 14th century disintegrated the Silk Road's political, cultural, and economic coherence. The western end of the road from the Byzantine Empire by Turkic tribes, spreading the seeds of a Turkic civilization that would later crystallize into the Ottoman Empire under Sunni Islam. The Han Chinese destroyed the Yuan dynasty in 1368, establishing the Ming dynasty and adopting an isolationist economic strategy.

At its peak as the world's biggest contiguous Empire, the Mongol Empire had a lasting impact, uniting vast swaths of land. Eastern and western Russia, as well as the western regions of China, are still united today. After the Empire's fall, Mongols may have been integrated into local people. Some of their descendants may have accepted local religions; for example, the eastern khanate adopted Buddhism, while the three western khanates acquired Islam, mostly under the Sufi influence. According to some accounts, Genghis Khan's conquests resulted in unparalleled levels of destruction in particular geographic areas, resulting in changes in Asia's population. Creating a writing system, a Mongol alphabet based on the characters of the Uyghur language, which is still used in Mongolia today, is one of the Mongol Empire's non-military achievements.