The Orthodox brotherhoods, first documented in 1463 (Lviv Dormition Brotherhood), were consolidated in the aftermath of the Union of Brest (1596) in order to oppose a rise in Roman Catholic proselytism, Jesuit expansionism and general Polonization. The brotherhoods attempted to stem the state-supported Catholic missionary activities by publishing books in the Cyrillic script and financing a net of brotherhood schools which offered education in the Ruthenian language. The famous Kyiv Mohyla Academy grew out of one such school under the umbrella of the Brotherhood Monastery in Kyiv. The Dormition Church, Lviv was financed by the brotherhood of the same name; its members also supported the Cossack risings in the east of Ukraine. The powerful Ostrogski family provided political support for their activities.