The study of the confraternity movement in early modern Ukraine is vital for our understanding of the unique place Ukrainian culture and society have occupied between Eastern and Western Christianity. Ukraine and Belarus were the only countries where Orthodox lay confraternities came into being. Their activities coincided with a period of crucial social and cultural change. Although structurally similar to their western European counterparts, the Eastern-rite confraternities developed their unique features. They introduced a spirit of competition between the two Ruthenian churchesñthe Orthodox and the Uniateñand contributed to an increase in the pace of Ruthenian socio-cultural growth. The schools attached to the Orthodox confraternities in several larger cities disseminated European humanist ideas and introduced generally accessible post-humanist education, while the confraternity presses promoted the development of scholarship and literature. Voluntary Brotherhood is a translation of one of the best works on early modern Ukraine to appear in the USSR after the 1920s. It is also a thoroughly revised and updated version of the original, Ukrainian-language work by one of Ukraine's leading historians. The author, Iaroslav Isaievych, has not only deleted terminology Soviet censors imposed before the book could be published in Kyiv in 1966, but has also broadened the scope of his analysis by utilizing a comparative approach and taking into account the scholarly literature on the subject published in the past four decades.