Robert ordained a Hungarian Dominican friar, Theodoric, as the first bishop of Cumania in early 1228. Pope Gregory IX confirmed Theodoric's consecration on 21 March of that year, and the diocese was subordinate to the Holy See in 1229. The episcopal see was on the Milcov River, but its exact location is unknown. The diocese included Burzenland and lands east of the Carpathian Mountains. Vlachs (Romanians) who belonged to the Orthodox Church were a significant part of the diocese's population. They did not follow the Catholic bishop, and persuaded many Catholic Hungarians and Saxons to accept their Orthodox bishops.