Pope gregory i: Did you mean...?

A c. 1450 illustration showing Pope Joan giving birth during a procession. Pope Joan was a legendary female pope of the Middle Ages said to have reigned from 855 to 858. Her existence is disputed. (Spencer Collection)

A 15-16th century manuscript illustration of Pope Joan, a legendary female pope of the Middle Ages said to have reigned from 855 to 858. Her existence is disputed. (Bibliothèque nationale de France).

The Council of Clermont in central France was held in November 1095 and witnessed Pope Urban II's (r. 1088-1099) historic call for the First Crusade (1095-1102) to capture Jerusalem for Christendom from its Muslim occupiers. The Pope's speech...

A statue of Pope Urban II (r. 1088-1099 CE) who called for the First Crusade (1095-1202 CE). Clermont-Ferrand, France.

A medieval manuscript illustration showing Pope Innocent III (r. 1198-1216 CE) and the crusaders of the Albigensian Crusade in southern France (1209-1229 CE). (Chronicles of Saint-Denis, British Library, London)

Pope Leo IX (r. 1049-1054), illustration from an illuminated manuscript, 11th century.

A manuscript depicting Frederick II (l. 1194-1250 CE) being excommunicated by Pope Innocent IV.

Robert Guiscard (c. 1015-1085) is proclaimed Duke of Apulia, Calabria, and Sicily by Pope Nicholas II, illustration from the Nuova Cronica of Giovanni Villani, 14th century.

A 1775 portrait by Pompeo Batoni of Pope Pius VI (r. 1775-99). (National Gallery of Ireland)

A c. 1914 photograph of Pope Pius X (1903-14). (National Portrait Gallery, London)