On This Day: July 20th

Canadian explorer Pierre Gaultier de Varennes et de La Vérendrye reaches the western shore of Lake Michigan.

Seventh Ottoman-Venetian War: The Ottoman Empire captures Nauplia, the capital of the Republic of Venice's "Kingdom of the Morea", thereby opening the way to the swift Ottoman reconquest of the Morea.

A fire in Oulu, Finland almost completely destroyed the fourth district, which covered the southern part of the city and was by far the largest of the city districts.

During the first Japanese invasion of Korea, Japanese forces led by Toyotomi Hideyoshi captured Pyongyang, although they were ultimately unable to hold it.

The Battle of Kellistown was fought on this day between the forces of the English led by Roger Mortimer, 4th Earl of March against the O'Byrnes and O'Tooles under the command of Art Óg mac Murchadha Caomhánach, the most powerful Chieftain in Leinster.

Treaty of San Germano is signed at San Germano between Holy Roman Emperor Frederick II and Pope Gregory IX. A Dominican named Guala is responsible for the negotiations.

Richard I of England officially invested as Duke of Normandy.

Rollo lays siege to Chartres.

Kardam of Bulgaria defeats Byzantine Emperor Constantine VI at the Battle of Marcellae.

Siege of Jerusalem: Titus, son of emperor Vespasian, storms the Fortress of Antonia north of the Temple Mount. The Roman army is drawn into street fights with the Zealots.