Date·Lore

On This Day · The 263rd day of the year

September 20

September 20 carries 10 recorded events spanning between 1260 and 2011. The Great Prussian Uprising among the old Prussians begins against the Teutonic Knights.

♍ZodiacVirgo ◈BirthstoneSapphire ❀Birth flowerAster

Compiled & reviewed by · Last reviewed July 13, 2026

What happened on September 20?

September 20 is the 263rd day of the year. It marks 10 notable events in history, dated between 1260 and 2011. Famous people born on September 20 include Jennifer Tour Chayes, Ernesto Teodoro Moneta and Sophia Loren.

The shape of the day

From 1260 to 2011, September 20 gathers 751 years of history. Most of the weight falls in the 20th century, where conflict is a recurring thread.

Virgo is the sign for September 20 — read more on the Virgo page, or see September's birthstone & birth flower.

Released on September 20

Movies, games, albums & shows

2025

  • Movie Disforia

2024

  • Game Parking Garage Rally Circuit
  • Game Frostpunk 2
  • Game Just a To the Moon Series Beach Episode

2023

  • Game Moonstone Island
  • Game Party Animals

Release data from TMDB & IGDB.

Events

10 notable moments
  1. 1260

    Prussian uprisings

    The Great Prussian Uprising among the old Prussians begins against the Teutonic Knights.

  2. 1498

    1498 Meiō earthquake

    The Nankai tsunami washes away the building housing the Great Buddha at Kōtoku-in; it has been located outside ever since.

  3. 1519

    Ferdinand Magellan

    Ferdinand Magellan sets sail from Sanlúcar de Barrameda with about 270 men on his expedition which ultimately culminates in the first circumnavigation of the globe.

  4. 1697

    Peace of Ryswick

    The Treaty of Ryswick is signed by France, England, Spain, the Holy Roman Empire and the Dutch Republic, ending the Nine Years' War.

  5. 1792

    Battle of Valmy

    French troops stop an allied invasion of France at the Battle of Valmy.

  6. 1920

    Irish War of Independence

    Irish War of Independence: British police known as "Black and Tans" burn the town of Balbriggan and kill two local men in revenge for an IRA assassination.

  7. 1971

    Hurricane Irene–Olivia

    Having weakened after making landfall in Nicaragua the previous day, Hurricane Irene regains enough strength to be renamed Hurricane Olivia, making it the first known hurricane to cross from the Atlantic Ocean into the Pacific.

  8. 1977

    Vietnam

    Vietnam is admitted to the United Nations.

  9. 2008

    Islamabad Marriott Hotel bombing

    A dump truck full of explosives detonates in front of the Marriott hotel in Islamabad, Pakistan, killing 54 people and injuring 266 others.

  10. 2011

    Don't ask, don't tell

    The United States military ends its "don't ask, don't tell" policy, allowing gay men and women to serve openly for the first time.

Famous birthday twins

Born on September 20

Jennifer Tour Chayes

b. 1956

American mathematician and computer scientist

Ernesto Teodoro Moneta

b. 1833

Italian soldier and journalist, Nobel Prize laureate

Sophia Loren

b. 1934

Italian actress

Victor Ponta

b. 1972

Romanian jurist and politician, 63rd Prime Minister of Romania

Matthias Erzberger

b. 1875

German publicist and politician

Laura Dekker

b. 1995

Dutch sailor

Aaron Burkart

b. 1982

German race car driver

Fabian Gottlieb von Bellingshausen

b. 1778

Russian admiral, cartographer, and explorer

Deaths

  • 2005Simon Wiesenthal
  • 1993Erich Hartmann
  • 1957Jean Sibelius
  • 1863Jacob Grimm
  • 1840José Gaspar Rodríguez de Francia
  • 1241Conrad II of Salzwedel

Holidays & observances

  • —Christian feast day: Agapitus (Western Christianity)
  • —Christian feast day: Eustace (Western Christianity)
  • —Christian feast day: Evilasius
  • —Christian feast day: Fausta of Cyzicus
  • —Christian feast day: Glycerius of Milan
  • —Christian feast day: Jean-Charles Cornay (one of Vietnamese Martyrs)
  • —Christian feast day: John Coleridge Patteson (commemoration, Anglicanism)
  • —Christian feast day: José Maria de Yermo y Parres

Historical facts, event summaries, and biographical lines above are adapted from Wikipedia under the Creative Commons Attribution-ShareAlike (CC BY-SA) license. DateLore adds curation, structure, and original editorial commentary. DateLore is not affiliated with the Wikimedia Foundation.

About the author

Roman Tailor compiles and reviews every date on DateLore. He's the writer and editor behind the site's editorial essays and the day-by-day almanac. Corrections and questions are welcome — read more about DateLore or get in touch.

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