January 18, 1520 – King Christian II of Denmark and Norway defeats the Swedes at Lake Åsunden.

January 19, 1520 – Sten Sture the Younger, the Regent of Sweden, is mortally wounded at the Battle of Bogesund.

June 15, 1520 – Pope Leo X threatens to excommunicate Martin Luther in papal bull Exsurge Domine.

June 30, 1520 – Spanish conquistadors led by Hernán Cortés fight their way out of Tenochtitlan.

October 21, 1520 – Ferdinand Magellan discovers a strait now known as Strait of Magellan.

November 1, 1520 – The Strait of Magellan is discovered, the passage immediately south of mainland South America, connecting the Pacific and the Atlantic Oceans, is first navigated by Ferdinand Magellan during the first global circumnavigation voyage.

November 8, 1520 – Stockholm Bloodbath begins: A successful invasion of Sweden by Danish forces results in the execution of around 100 people.

November 10, 1520 – Danish King Christian II executes dozens of people in the Stockholm Bloodbath after a successful invasion of Sweden.

November 28, 1520 – After navigating through a strait at the southern end of South America, three ships under the command of Portuguese explorer Ferdinand Magellan reach the Pacific Ocean, becoming the first Europeans to sail from the Atlantic Ocean to the Pacific.

December 10, 1520 – Martin Luther burns his copy of the papal bull Exsurge Domine outside Wittenberg’s Elster Gate.

March 3, 1520 – Matthias Flacius, Croatian Protestant reformer (d. 1575)

August 10, 1520 – Madeleine of Valois, French-born Queen consort of the Scots, wife of James V of Scotland (d. 1537)

October 5, 1520 – Alessandro Farnese, Italian cardinal (d. 1589)