St. Malachy was a 12th century prophet who provided prophetic mottoes for each pope from Celestine II in the 12th century until the final pope, Petrus Romanus, or Peter the Roman, who, according to the prophecy, would sit on the seat of St. Peter during the day of Judgment. St. Malachy provided mottoes for 112 popes, which, some believe, match up with every pope up until Pope Benedict XVI and even Pope Francis, who would, according to the prophecy, currently be sitting on the throne of St. Peter as the final pope or as Peter the Roman in the Day of Judgment.

This edition contains the prophecies in English and in the original Latin and, for all of the popes before 1590, a biographical note. A brief explanation of each motto and an illustration of the coat of arms are included for all of the popes, except for those who are left undiscovered.