On This Day: August 20th

Former Grand Pensionary Johan de Witt and his brother Cornelis are lynched by a mob in The Hague.

The Battle of Lens is the last major military confrontation of the Thirty Years' War, contributing to the signing of the Peace of Westphalia in October that year.

On the third day of battle, philosopher and general Wang Yangming defeats Zhu Chenhao, ending the Prince of Ning rebellion against the reign of the Ming dynasty's Zhengde Emperor.

The Second Battle of Olmedo takes places as part of a succession conflict between Henry IV of Castile and his half-brother Alfonso, Prince of Asturias.

At the conclusion of the interrogation of the leaders of the Knights Templar, the three papal investigators, Cardinals Bérenger Frédol, Etienne de Suisy and Landolfo Brancacci, write the "Chinon Parchment", in which they affirm that the accused Templars had confessed, done penance, and were absolved of heresy.

Believing Saladin had reneged on ransom promises, Richard I of England initiates the massacre at Ayyadieh, beheading 2,700 captive Muslim soldiers and another 300 women and children seized at the Fall of Acre.

The first King of Hungary, Stephen I, and his son, Prince Emeric, are canonized, a date now celebrated as a National Day in Hungary.

Battle of Acheloos: Tsar Simeon I of Bulgaria decisively defeats a Byzantine army.

Marking the first great wave of Muslim conquests and the rapid advance of Islam outside Arabia, Arab forces led by Khalid ibn al-Walid defeat the Byzantine Empire and take control of the Levant.

Agrippa Postumus, maternal grandson of the late Roman emperor Augustus, is executed by his guards while in exile.