The Mongols defeated the Alans after convincing the Kipchaks to desert them through pointing at their likeness in language and culture. Nonetheless, the Kipchaks were defeated next. Under "khan" Köten, Kipchaks fled to the Grand Principality of Kiev (the Ruthenians), where the Kipchaks had several marriage relations, one of which was Köten's son-in-law Mstislav Mstislavich of Galicia. The Ruthenians and Kipchaks forged an alliance against the Mongols, and met at the Dnieper to locate them. After an eight-day pursuit, they met at the Kalka River (1223). The Kipchaks, who were horse archers like the Mongols, served as the vanguard and scouts. The Mongols, who appeared to retreat, tricked the Ruthenian–Kipchak force into a trap after suddenly emerging behind the hills and surrounding them. The fleeing Kipchaks were closely pursued, and the Ruthenian camp was massacred.