Election of Pope Boniface V, 69th successor of Peter. His pontificate would last six years and two days. Yet his pontificate would be delayed for eleven months and would be embittered by wars for the Crown of Italy. He would institute the privilege of sanctuary for those persecuted who sought refuge in churches. It would also be during his papacy when the prophet Mohammed would begin preaching, giving vent to one of the greatest threats to Christianity the world had ever known and plunge Europe into centuries of war against Islamism.
Death of Saint Thorlac Thorhallsson, Icelandic bishop and reformer who insisted on clerical celibacy and stricter discipline in his see as Bishop of Skalholt. Though a cult honoring him rose up it was never formally recognized by Rome. He is considered the patron saint of Iceland.
Death of Hendrik de Guise, French leader of the Catholic League by the French Hugenots which would gain in power after his death, eventually declaring war against the French King Louis XIII on this same date in 1620. Hendrik's cousin was the Archbishop of Reims.
Pope Pius XI issues his first encyclical Ubi arcano Dei consilio on the peace of Christ in the Kingdom of Christ in a plea for world peace in the aftermath of World War I.
Pope Pius XII publishes his ninth encyclical Orientales omnes Ecclesias commemorating the 350th anniversary of the reunion with Rome of the Ruthenian Church.