The Oxford Dictionary of Popes (Oxford Quick Reference)

Since World War II and especially since the election of Pope John XXIII in 1958, the papacy--the oldest of all Western institutions--has attracted steadily growing interest from non-Christians as well as Christians.
Written for people of every religious allegiance and none, J.N.D. Kelly's biographical dictionary presents a wealth of information about the papacy and the astonishing succession of churchmen who have loomed large on the world scene for almost two thousand years. It contains concise accounts not only of all the officially recognized popes from St. Peter to John Paul II, but also of all their irregularly elected rivals, the so-called antipopes. It also includes an appendix which records the once generally accepted, but long since discarded, legend that at some date in the ninth, tenth, or eleventh century a female pope called Joan existed.
The Dictionary provides an entry for each pope and antipope which covers--except where (as in the early centuries) information is unavailable--his family and social background and pre-papal career, as well as his activities in office. Each entry has a separate select bibliography, usually including references to the primary source for the pope's life and his official acts. Arranged chronologically, the volume places each pope in the proper historical context and offers, in effect, a continuous history of the papacy.
Based on careful research, but eminently readable, this reference work reveals an extraordinarily diverse group of men who have designated themselves as St. Peter's successors, and records their varying involvement in great power politics, personal or family aggrandizement, patronage of the arts, theological controversy, or spiritual leadership. It presents a graphic and moving picture of the fluctuating fortunes of the Christian Church centered in Rome, sometimes submerged by secular forces, but at other times, staging a spectacular revival and confronting the world (as today) with a daunting challenge.