Browse Historical Events by Day: What Happened on September 20th?

Arab forces led by Caliph Umar conquer the city of Alexandria, Egypt, ending Byzantine control and marking a significant moment in the Arab conquests.

Byzantine forces led by Emperor Constantine VII defeat the Bulgarian army at the Battle of Achelous, securing Byzantine control over the Balkans.

The Crusaders, led by Godfrey of Bouillon, capture the city of Jerusalem from the Fatimid Caliphate, marking the conclusion of the First Crusade.

The Crusaders, led by Sigurd I of Norway, arrive in Lisbon, Portugal, and establish a temporary alliance with King Afonso I against the Moors.

The Battle of Mühldorf occurs during the Bavarian Civil War, where forces loyal to Emperor Louis IV defeat the Habsburgs, securing Louis' position as Holy Roman Emperor.

The Treaty of Lodi is signed, bringing an end to the conflict between the Italian city-states of Milan, Florence, and Naples, establishing peace in the region.

Portuguese navigator Ferdinand Magellan, with five ships and a crew of 270 men, sets sail from Sanlucar de Barrameda in southern Spain, on what become the first circumnavigation of the world and the first European explorer to reach the Pacific Ocean from the Atlantic. Magellan himself died during the tumultuous three year voyage, with Spaniard Juan Sebastian Elcano completing the journey from the Phillipines back to Spain with a final crew of only 18 men on September 6 1522. Despite Magellan’s tragic end, his legacy has become synonymous with exploration and geography—including the Strait in South America that still bears his name. More

The first representative assembly in America, the House of Burgesses, meets in Jamestown, Virginia.

The Battle of Edgehill takes place, marking the first major conflict of the English Civil War.

The Treaty of Ryswick is signed, ending the Nine Years' War between France and the Grand Alliance of European powers.

1806, September 20 - After more than two years exploring the western wilderness, Lewis and Clark's Corps of Discovery arrived at the frontier village of La Charette, in modern Missouri. More

The Papal States, the last remnants of the Papal territories, are incorporated into the Kingdom of Italy, marking the end of the temporal power of the Pope.

The Provisional Irish Republican Army (IRA) carries out a bombing in Brighton, England, targeting the Conservative Party conference. Although Prime Minister Margaret Thatcher survives, five people are killed in the attack.

The War in Afghanistan begins when the United States, supported by its allies, launches military operations against the Taliban regime in response to the 9/11 attacks.

The Colombian government and FARC sign a peace agreement.

Hurricane Maria devastates Puerto Rico.

Millions participate in a Global Climate Strike, led by Greta Thunberg.