Pope Leo X: Did you mean...?

A gold nomisma coin depicting Byzantine emperor Leo III (r. 717-741 CE). (British Museum, London)

A gold solidus (nomisma) coin of Byzantine emperor Leo V the Armenian (r. 813-820 CE). The reverse side shows his son Constantine. (Classical Numismatic Group, Inc. http://www.cngcoins.com)

A portrait bust of Byzantine emperor Leo I (r. 457-474 CE). (Louvre Museum, Paris)

A gold solidus coin depicting Constantine V, emperor of the Byzantine empire between 741 and 775 CE (right) and Leo III (r. 685-741 CE)

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)

The medieval indulgence was a writ offered by the Church, for money, guaranteeing the remission of sin, and its abuse was the spark that inspired Martin Luther's 95 Theses. Luther (l. 1483-1546) claimed the sale of indulgences was unbiblical...

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).

Built in the seventh century BCE, the ancient city of Byzantium proved to be a valuable city for both the Greeks and Romans. Because it lay on the European side of the Strait of Bosporus, the Emperor Constantine understood its strategic importance...

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)