Europa Sacra provides information on medieval Church prelates including information on all 13,00 medieval bishoprics, archdioceses and patriarchates under obedience to Rome, as well as Prosographical information on 30,000 bishops, archbishops and patriarchs. Europa Sacra draws its information from: C. Eubel, Hierarchia catholica medii aevi... ab anno 1198 [1st and 2nd edns. Münster, 1898ff] and P.B. Gams, Series episcoporum ecclesiae catholicae [Regensburg, 1873-86]. (Updates vary)