Peter's Rock in Mohammed's Flood, from St. Gregory the Great to St. Leo IIIAllies, T. W. (Thomas William)
Crises in the History of the Papacy A study of twenty famous popes whose careers and whose influence were important in the development of the church and in the history of the worldMcCabe, Joseph
The History of the Popes: From the Foundation of the See of Rome, to the Present Time, 3rd Ed. Vol. 1Bower, Archibald