[4] In either case, the two peoples were part of the Cuman–Kipchak confederation, known as Cumania in Latin, Desht-i Qipchaq in Islamic sources (from Turkic), and Polovtsy in East Slavic.

[7] According to some arguments, his father was Könchek, who changed the old Cuman system of government whereby rulership went to the most senior tribal leader; he instead passed it on to his son Köten.

[8] Köten and his brother Somogur are first mentioned by Russian annals in 1202 (but in fact, it occurred in 1205), when supported Rurik Rostislavich in the war against Roman Mstislavich.

The Cuman–Kipchak confederation under Köten and a Rus army of 80,000 men under his son-in-law Mstislav the Bold fought a battle at the Kalka River (Kalchyk, near Mariupol) against a Mongol contingent commanded by Jebe and Sübötäi.

[citation needed] Following the battle, some historians – Joseph von Hammer-Purgstall, István Gyárfás, Josef Markwart – argue that Köten and his Cumans settled down along the southern Volga and lived there until their expulsion in the end of the 1230s.

[9] For instance, in 1226, a boyar named Žiroslav threatened those who disobeyed Mstislav that he would hand them over to his father-in-law Köten, who destined for them a cruel fate.

His Cumans and the Prince of Halych jointly fought against Hungary in that year (or in 1230), while the Hungarians commanded by Duke Béla was supported by the baptized chieftain Bortz.

After several exchanges of envoys from both parties, the aforesaid Kuten set out with his people to come to Hungary.After returning from Magna Hungaria in 1236, Friar Julian informed King Béla IV of Hungary of the Mongols, who had by that time reached the Volga River and were planning to invade Europe.

Fleeing the Mongols, at least 40,000 Cumans under the leadership of Köten approached the eastern borders of the Kingdom of Hungary and demanded admission in 1239.

[9] The monarch only agreed to give them shelter after Köten promised to convert together with his people to Christianity, and to fight against the advancing Mongols.

Köten accepted the conditions and Béla IV, who, with his entourage, went to the border to receive him, granted asylum to the Cuman refugees.

This event most plausibly occurred at the Easter of 1239 (27 March), while Gyula Pauler considered the arrival of the Cumans took place in the autumn of 1239.

In contrast to the narration of Master Roger, Alberic of Trois-Fontaines' chronicle claims that Köten came to Hungary after being captured by Hungarians in battle, disguised as a Mongol.

His Hungarian subjects thought that he was biased in the Cumans' favor, thus "enmity emerged between the people and the king", according to Master Roger.

King Béla then installed front line defenses at the Carpathian Mountains, after which he returned to Buda and called a council of war and ordered unity against the Mongols.

They blamed the Cumans acted as "advance guard" of the Mongols, to get to know the conditions of the country, to learn their language, and when they are informed of their arrival, to start the fight against the Hungarians, so that they will be able to take possession of the Verecke Pass (or "Russian Gate", present-day Veretskyi Pass, Ukraine) more easily, according to Master Roger, despite the fact that the Mongols had attacked Köten's people for nearly 20 years.

This chaos pushed Béla IV into a corner; feeling he needed to show his strength and keep the rebellious barons on his side, he ordered Köten and his family, along with other chief men, to be placed under house arrest.

Duke Frederick II of Austria, who arrived to assist Béla against the invaders, defeated a small Mongol troop near Pest.

[4] Following the Mongol invasion, Béla IV invited the Cumans, who had in 1241 left Hungary, to return and settle in the plains along the river Tisza.

[4] The video game Age of Empires II: Definitive Edition contains a five-chapter campaign titled "Kotyan Khan", starting with his rallying the remains of the Cuman-Kipchak confederation and concluding with the arrival of the Cumans in Bulgaria as well as their later return to Hungary.