On This Day: October 21st

João Álvares Fagundes discovers the islands of Saint Pierre and Miquelon, bestowing them their original name of "Islands of the 11,000 Virgins".

Martin Luther joins the theological faculty of the University of Wittenberg.

Japanese Emperor Go-Kameyama abdicates in favor of rival claimant Go-Komatsu.

Election of Gregory VIII following the death of Pope Urban III.

Zengi, atabeg of Aleppo, takes Baalbek from the Burid dynasty.

First Crusade: Crusaders led by Godfrey of Bouillon, Bohemund of Taranto, and Raymond IV, Count of Toulouse, begin the Siege of Antioch.

A Seljuk Turkish army successfully ambushes the People's Crusade at the Battle of Civetot.

El Cid and his forces defeat a larger army of the Almoravids in the battle of Cuarte.

Election of Pope Conon following the death of Pope John V.

Sixty-five days after being exiled by the Emperor Maxentius to Sicily, Pope Eusebius dies.