BATU KHAN, Mongol chief, the grandson of Jenghiz Khan, succeeded his father, Juji, as king of the Kipchaks in 1223, and in 1229 followed the new khan, Ogdai, in his expedition to China. On his return the latter sent Batu to Europe at the head of an in vading army which spread over Russia, Poland and Hungary, and in 1236 attacked the Bulgars of the Volga, and advanced west ward to Kiev, and Hungary in the following years. Western Europe was saved only by the death of Ogdai in 1241, which ne cessitated Batu's return to take part in the election of a new khan. After this he settled on the river Akhtuba, and lived in great splendour at his capital, Sarai, in the present gubernia of Astrak han. At the death of Batu in 1255 his brother Bereke succeeded to his kingdom, which extended from Lake Balkash as far west as the confines of modern Russia. See MONGOLS.