Kazimierz Bem, Ph.D. (2007, Vrije Universiteit Amsterdam), is pastor of First Church in Marlborough (Congregational) UCC in Massachusetts, USA. He received his M.Div. and S.T.M. degrees from Yale Divinity School in 2010 and 2012. He is the author of many articles on Calvinism in Polish-Lithuanian Commonwealth and the book Biographical Dictionary of Reformed Clergy. Pastors and Deaconess of the Lesser Poland and Warsaw Consistory 1815-1939 (Wydawnictwo Naukowe Semper, 2015).

This book offers an in-depth history of Calvinism in the Polish-Lithuanian Commonwealth 1548-1648. It traces the development of polity, liturgy, piety and church discipline. Bem questions the prevailing narrative of decline post 1570 and argues that the three Reformed Churches in fact continued to develop and flourish until the 1630s.