Battle of the Kalka River

The Battle of Kalka River has struggled between the Mongol Empire and a coalition of numerous Rus' princes, notably Kiev and Halych, and the Cumans, headed by Jebe and Subutai the Valiant. Mstislav, the Bold and Mstislav III of Kiev, were in charge of them jointly. The fight took place on the banks of the Kalka River in today's Donetsk Oblast, Ukraine, on May 31, 1223, and culminated in a clear Mongol triumph. A Mongol force led by generals Jebe and Subutai moved into Iraq-i Ajam after the Mongol conquest of Central Asia and the subsequent collapse of the Khwarezmian Empire. Jebe asked Mongolia's monarch, Genghis Khan, to continue his conquests for a few years before rejoining the main army via the Caucasus. While waiting for Genghis Khan's response, the two embarked on an expedition against the Kingdom of Georgia. After passing across the Caucasus and conquering a coalition of Caucasian tribes before defeating the Cumans, Genghis Khan granted the two permission to go on their journey. Cuman Khan escaped to the court of his son-in-law, Prince Mstislav the Bold of Halych, whom he persuaded to aid him in the war against the Mongols. Mstislav the Bold created a Rus' princes' coalition, which included Mstislav III of Kiev. At initially, the united Rus' army destroyed the Mongol rearguard. For several days, the Rus' followed the Mongols, feigning retreat and spreading out their troops. Finally, on the banks of the Kalka River, the Mongols came to a halt and formed a battle formation. Mstislav the Bold and his Cuman friends assaulted the Mongols before the rest of the Rus' army arrived, and they were destroyed. Several other Rus' princes were beaten in the subsequent chaos, and Mstislav of Kiev was forced to retire to a fortified camp. He surrendered after three days of detention in exchange for a guarantee of safe conduct for himself and his troops.  The Mongols killed them and executed Mstislav of Kiev when they surrendered. However, Mstislav the Bold managed to flee, and the Mongols returned to Asia to join Genghis Khan.

In 1219, Genghis Khan, the Mongol Khan, attacked the Khwarezmian Empire in revenge for the deaths of his diplomats. Genghis Khan and his generals defeated the Khwarezmian troops and forced the empire to fall apart in a three-year struggle. Then, on an island in the Caspian Sea, the Khwarezmian Sultan Ala ad-Din Muhammad died of illness, leaving his son, Jalal ad-Din Mingburnu, landless. When Jebe (one of the Mongol generals chasing Muhammad) learned of Ala ad-Din Muhammad's death, he requested permission from Genghis Khan to continue his conquests for a year or two before returning to Mongolia through the Caucasus. While waiting for Genghis' response, Jebe and Subutai (another general chasing Muhammad) commanded a force of 20,000 soldiers, each of whom was in charge of a tumen. As they proceeded into Persian Iraq (Iraq-i Ajam) and Azerbaijan, sacking the cities of Rey, Zanjan, and Qazvin, they left a trail of ruin in their wake. Finally, the city of Hamadan gave up without a fight.

Meanwhile, Ozbeg, Azerbaijan's Atabeg, preserved his city, Tabriz, and saved his country by providing the Mongols with a huge sum of money, clothes, and horses, which were the Mongols' most powerful weapons. The Mongols pushed north from Tabriz and established a winter base in the Mugan Steppes. The advent of Kurdish and Turcoman freebooters, who volunteered their services to the Mongols, bolstered the army.

Caucasus Raid

At the same time, Jebe and Subutai's focus had shifted to something else. They launched a survey into the Kingdom of Georgia in January and February 1221, coming across the Kura River. The Mongols' objective was to loot the land, not conquer it, and the Kurds and Turcoman freebooters were first dispatched. However, Georgian King George IV Lasha led 10,000 soldiers forward and drove the Mongols back near Tbilisi. Although the Mongols retreated, they continued to assault the Georgian army. The Mongols returned to Azerbaijan in March 1221 and besieged Maragheh, employing captives as vanguards to endure the brunt of each assault. By the epilogue of the month, they had taken control of the city and executed most of the inhabitants. While the Caliph remained at Iraq-i Ajam with a tiny force, Jebe and Subutai intended to move south, take Baghdad, the Abbasid Caliphate's capital, and hold it for ransom. Instead, the Mongols shifted their attention to Hamadan once more.

On the other hand, the city's commanders refused to submit, and the city's defenders inflicted heavy fatalities on the Mongol army before capturing and plundering the city. The Mongols pushed north into Georgia once more in late 1221, this time through the Kura River. Near Tbilisi, a 30,000-strong Georgian-Armenian force was formed. The Mongols were further reinforced with 30,000 troops, and neighbouring Turkmen tribes provided additional help. While the main Mongol force pretended to flee, Jebe set up an ambush with 5,000 soldiers. After beating the Turkmen, the Georgian cavalry followed Subutai's army and was slaughtered when Jebe closed the trap. King George was severely wounded, and the Georgian army suffered a devastating defeat. The Mongols then went on a plundering spree in southern Georgia.

After Genghis Khan granted Jebe permission, the Mongols proceeded on Derbent, which refused to submit, with Subutai as their second-in-command. In exchange for the services of ten guides to accompany them through the Caucasus, Jebe pledged to spare the city. The Mongols killed one of the guides to warn them against playing any pranks. The Mongols paid a high price for crossing the Caucasus, leaving their siege engines and losing hundreds of soldiers to the cold. After passing over the Caucasus, the Mongols were confronted by an alliance of tribes residing north of the Caucasus, the Lezgians, Alans, and Cherkesses. They had amassed a force of about 50,000 men. The Cumans, a Turkic tribe that controlled a vast khanate spanning Lake Balkhash to the Black Sea, joined them. The Volga Bulgars and Khazars were also persuaded to join the Cumans. Koten, the Cuman Khan, delegated command of his army to his brother, Yuri, and his son, Daniel. The league's first fight with the Mongols was indecisive. Still, the Mongols were able to persuade the Cuman to quit the alliance by reminding them of the Turkic-Mongol friendship and offering them a part of the spoils taken from the Caucasian tribes. With this agreement in place, the Mongols invaded and defeated the alliance's army. Before attacking Astrakhan, the Mongols attacked the Cumans, divided into two groups while heading home, defeating both armies and murdering all the captives. Then, as the Cumans retreated in a north-westerly direction, the Mongols began chasing them. The Venetians dispatched a delegation to the Mongols, and the two sides formed an agreement in which the Mongols pledged to demolish any other European trading station they encountered. Jebe dispatched a force to Crimea, where the Republic of Genoa maintained trading posts as the Mongols pursued the Cumans. The Genoese city of Soldaia was conquered and ravaged by the Mongols. Meanwhile, Koten escaped to the court of Prince Mstislav the Bold of Halych, his son-in-law. "Today, the Mongols have seized our country, and tomorrow they will take yours," he told Mstislav.

On the other hand, the Cumans were neglected for over a year, even though the Rus had been subjected to Cuman attacks for decades. The Rus retaliated when word reached Kiev that the Mongols were advancing down the Dniester River. Mstislav formed a support group of Kievan Rus princes, including Mstislav III of Kiev and Prince Yuri II of Vladimir-Suzdal. The Rus princes gathered their forces and marched towards the rendezvous spot.

Initial Moves

The exact number of soldiers who fought in the fight is debatable. The fact that no historical sources provide the number of men present during the fight is a key element in this, leaving contemporary historians to estimate the number of men. According to historian Leo de Hartog, the Rus' army numbered 30,000 men, but Richard Gabriel and Hector Hugh Munro believe that the army numbered 80,000. De Hartog also puts the Mongol army's size at 20,000 soldiers, whereas Gabriel puts it at about 23,000 troops. Many of these figures, according to historian John Fennell, an expert on Kievan Rus and early Russian history who is well-versed in the primary sources, are formulaic or exaggerated, and that the numbers given in the Russian sources (there are no Mongol or Polovtsian sources, at least none that have survived, and other sources from other cultures, if they exist, are dubious) are formulaic or exaggerated. The information presented in the Novgorod First Chronicle and the Primary Chronicle would suggest that the Rus' troops had a total of 11,000 soldiers. Still, Fennel believes that even these figures are exaggerated.

While Russian historians in the Soviet era gave estimates of 80,000-100,000, current Russian historians have taken a revisionist approach, with a consensus settling on far lower figures, despite the Mongols' numerical advantage. In 2013, Russian historian D.G. Khrustalev calculated that the Rus had 10,000 troops (including mercenaries) and the Cumans had 5,000 cavalries, totalling 15,000 men. Carl Sverdrup estimates the army to be around 8,000 men and claims that 30,000 and 80,000 are exaggerations. Given the extent to which the Mongols went to dislodge its formations, it was clear that they thought it was a formidable force. The Mongols were waiting for reinforcements from Jochi, Genghis Khan's eldest son, who was campaigning in the Aral Sea on the east bank of the Dnieper River when the Rus' army moved. Jochi, on the other hand, had become unwell so that no reinforcements would be arriving. At the same time, the Mongols were being pursued by the Russians. The princes of Halych and Volhynia marched their troops south along the river, while the princes of Kiev and Chernigov marched north, while the army of Kursk approached from the front. The Cumans attempted to attack the Mongol army's rear at the same moment. When Jebe found this, he dispatched ten envoys to the Prince of Kiev. According to the envoys, the Mongols had no conflict with the Rus and were only assaulting the Cumans; they also reported that the Mongols were heading east, away from the Rus' towns. Mstislav of Kiev killed the envoys, and the Mongols replied by sending another group of diplomats who proclaimed war. When Jebe and Subutai learned of the Rus' activities, they began heading east, away from the Rus, because that was the only way they could get away. They did, however, leave a 1,000-strong rearguard under the direction of an officer named Hamabek to report on the Rus' movements and act as bait. Mstislav the Bold soon arrived at the river opposite the rearguard, and it was clear that no prince had been named commander-in-chief. As a result, all of the princes were free to do as they wanted. Mstislav eventually made it over the river, despite heavy arrow fire. However, the Rus' numbers were too large when they arrived, and the Mongols were slaughtered to the last man.

Rus' Attack

The Mongol army rotated to face their pursuers along the Kalka River (where the river's location is now uncertain, but it is likely to be the Kalchik River, which drains into the Sea of Azov) after dragging out the Rus forces for nine days in a simulated retreat. The fight and the princes' chase back across the steppe are barely mentioned in passing in Russian primary sources. The chronicles mention which princes participated and died, but not much else in terms of troops or losses. In terms of the combat itself, the chronicles claim that the Polovtsy (Cumans) broke and retreated without fighting, causing great confusion within the Russian lines and resulting in their massacre by the Mongols.

Rus' Defeat

When most of the alliance army had crossed the Kalka River, the Mongols attacked. Because the coalition rout began incredibly quickly, the Mongols appear to have caught the coalition forces off guard in a quick transition from horse archer fire to massed cavalry charges. The Rus forces bringing up the rear had not yet arrived on the battlefield when the front ranks were dissolving. The soldiers of Volhynia and Kursk created a breach in their line to allow the Cumans to leave. The Mongol heavy cavalry, on the other hand, charged through the freshly formed breach and encircled them. Chernigov's army was advancing when they clashed head-on with the retreating Cumans, unaware that the fight had begun. The Mongol cavalry took advantage of the uncertainty in the Chernigov line and assaulted, causing the line to crumble, using smoke bombs to impair the coalition's ability to communicate. Prince Mstislav of Chernigov was killed as a result of this. At the same time, Mongol wings closed in on the broken Russian army, shutting it off from escaping. The encircled Russians were bombarded with round after volley, with horse assaults aimed at any weak spots in the line. Some of the army, commanded by Mstislav the Bold, managed to cut their way through the Mongol ring and flee while the Mongols carried out their devastation. Mstislav of Kiev arrived in time to witness the Rus' army leaving. He fled to his stockaded camp on a hill near the Dnieper with his troop of 10,000 soldiers. Unfortunately, Mstislav of Kiev's soldiers were surrounded by the pursuing Mongol army, which began to besiege the camp.

The Intervention of Brodnici

Mstislav of Kiev and the Kievan army held out for three days, but Ploscânea ultimately forced them to submit. Ploscânea, on the other hand, misled the Slavs and handed them over to the Tatars; Ploscânea was originally associated with the Slavs and Cumans and was the leader of the Brodnici, who lived in what is now Moldova and Romania. The Mongols killed the Kievan army, including Mstislav of Kiev and numerous other noble prisoners, after gaining possession of the camp.

According to Richard Gabriel, the fight was a humiliating setback for the Rus' rulers, who lost 50,000 soldiers, while the Mongol casualties were minor. All of the coalition forces involved were trapped with their backs to the river and had no viable escape route. Mstislav the Bold was the only one who was able to save some of his troops. The Major Chronicle, one of the Rus' primary sources, lists 10,000 slain, whereas the Nikonian Chronicle, much later (and less trustworthy), lists 60,000. The most trustworthy Novgorodian First Chronicle, written contemporaneously with the fight, offers no statistics at all but does claim that just one out of every ten men returned home, implying that the number of the slain was almost the whole army. The injured Daniel of Volhynia and Mstislav the Bold, both Rus princes, managed to flee the fight. With the noteworthy exception of Vladimir-Suzdal, this fight was a severe defeat since many Rus princes lost many of their troops. "The rest of Subutai's campaign has entered the annals of military history as one of the greatest adventures of horse combat," writes historian Robert Marshall. The Mongols killed Mstislav of Kiev and the Kievan nobles with the usual Mongol proviso reserved for royalty and nobility: no bloodshed. Mstislav and his nobles were buried and suffocated beneath the Mongol general's victory platform at the triumph feast.

Meanwhile, Mstislav the Bold and the rest of his army made it to the western bank of the Dnieper. Mstislav burned all the boats he could locate to prevent the Mongols from crossing the Dnieper on the western bank. The people of Rus shuddered in terror after the fight, fearful of an unknown scourge that had risen from the boundary and slain the bloom of their army. On the other hand, the Mongols were not there to conquer; instead, they marched east after looting. The Mongols chased the Prince of Halych and ravaged a few towns in the south before turning back, which the Rus anticipated would happen. Near modern-day Volgograd, the Mongol army crossed the Volga River and proceeded into Volga Bulgaria. The Mongol army routed the Bulgars and marched east to meet up with their allies. Following this, the Mongols attacked the Qanglis Cumans, who had previously aided their fellow Cumans in the Caucasus. They battled the Cuman army in the Ural Mountains, defeating and killing the Khan before demanding tribute. The Mongols then turned east, meeting Genghis Khan and the remainder of the Mongol army on the steppes east of the Syr Darya River. Genghis Khan was ecstatic about his generals' accomplishments and lavished praise on Jebe and Subutai. Jebe, on the other hand, did not live to see the end of the campaign; he died shortly after. The expedition's significance was enormous. The Mongols rode 5,500 miles (8,900 km) in three years, making it the world's longest cavalry attack. Subutai also had many spies stationed in Russia who supplied regular updates on what was going on in Europe and Russia. Subutai and Batu conducted another invasion in 1237, conquering the Kievan Rus' with 120,000 soldiers.