The Roman Catholic Diocese of Cumania was a Latin-rite bishopric west of the Siret River (in present-day Romania) from 1228 to 1241. The lands incorporated into the diocese had been dominated by the nomadic Cumans since about 1100. Catholic missions began after Andrew II of Hungary granted Burzenland to the Teutonic Knights in 1211. After Andrew expelled the Knights from the territory in 1225, Dominican friars continued the Cuman mission. Robert, Archbishop of Esztergom baptized Boricius, an influential Cuman chieftain, two years later.