523 John I was elected Roman Catholic pope. He ended the Acacian Schism, bringing reunification of the Eastern and Western churches by restoring peace between the papacy and the Byzantine Emperor Justin I. He also set the rules for the Alexandrian calendar computation of the date of Easter, which was eventually accepted throughout the West.
1415 Hundred Years War: King Henry V of England army landed on mouth of the Seine River, and organized the siege of the town of Harfleur (now part of Le Havre).
1422 William Caxton, first English printer, was born. 1
Francis I of France
516 The Treaty of Noyon between France and Spain was signed. Francis I of France recognized Charles's claim to Naples, and Charles V, Holy Roman Emperor recognized Francis' claim to Milan.