J. N. D. Kelly.
The Oxford Dictionary of Popes.
OUP. 1986
Writing for people of every religious allegiance and none,
John Kelly gives here 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.
He also records in an appendix the once generally credited, but long discarded,
tradition that at some date in the ninth, tenth, or eleventh century there was a popess called Joan.
Each pope and antipope has an entry which covers his family and social background and pre-papal career as well as his activities in office. The entries are arranged chronologically so that each pope can be studied in his own historical context; the book is thus a continuous history of the papacy which has an unbroken existence of almost 2,000 years, and it reveals how, for much of that history, spiritual and temporal power have been inextricably mingled in the person of the pope.
Each entry provides a select bibliography, and the inclusion of an alphabetical list of popes and antipopes and a full index make this dictionary a convenient work of reference.