Events of 1811

January–March

• January 3 – An unsuccessful slave revolt is led by Charles Deslandes in St. Charles and St. James, Louisiana.

• January 22 – The Casas Revolt begins in San Antonio, Texas.

• February 5 – British Regency: George, Prince of Wales becomes Prince Regent because of the perceived insanity of his father, King George III of the United Kingdom.

• March 1 – Citadel Massacre: Egyptian ruler Mohammed Ali kills the last Mamluk leaders.

• March 13 – Battle of Lissa (1811): The British fleet defeats the French.

• March 22 – The Commissioners' Plan of 1811 for Manhattan is presented.

• March 25 – The Great Comet of 1811 is discovered by Honoré Flaugergues.

• March 27 – Battle of Anholt: The British navy defeats Denmark.

April–June

• April 5- April 6 – Revolutionary riots occur in Buenos Aires.

• May 14 – Paraguay declares independence from Spain.

• May 16 – Battle of Albuera: Spain, Portugal and Great Britain defeat the French.

• June 9 – The Great fire of the Podil breaks out in Kiev, Ukraine.

July–September

• July 5 – Venezuela declares its independence from Spain.

• July 11 – Italian scientist Amedeo Avogadro publishes his memoire about the molecular content of gases.

• August 3 – First ascent of Jungfrau, third highest summit in the Bernese Alps,

• September – Nathan of Breslov leads the first annual Rosh Hashana kibbutz (pilgrimage) of Breslov Hasidim to the grave of Rabbi Nachman of Breslov in Uman, Ukraine.

October–December

• October 11 – Inventor John Stevens' boat, the Juliana, begins operation as the first steam-powered ferry (service between New York, New York, and Hoboken, New Jersey).

• November – Luddite uprisings begin in northern England and the Midlands.

• November 6 – Battle of Tippecanoe: American troops led by William Henry Harrison defeat the Native American chief Tecumseh.

• November 17 – José Miguel Carrera, Chilean founding father, is sworn in as President of the executive Junta of the government of Chile.

• December 16 – The New Madrid earthquake in Mississippi Valley near New Madrid reverses the course of the river for a while. Other earthquakes along the fault occur on January 23, 1812 and February 7, 1812.

Ongoing events

• Argentine War of Independence (1810–1818)

• Black War (1804–1835)

• Bolivian Independence War (1809–1824)

• Gunboat War (1807–1814)

• Mtetwa Empire Expansion

• Napoleonic Wars (1799–1815) – Peninsular War

• Russo-Persian War (1804-1813)

• Russo-Turkish War, 1806-1812

Births

January–June

• January 9 – Gilbert Abbott à Beckett, English writer (d. 1856)

• February 3 – Horace Greeley, American journalist, editor, and publisher (d. 1872)

• February 6 – Henry George Liddell, English clergyman (d. 1898)

• March 20 – Napoleon II of France (d. 1832)

• March 21 – Nathaniel Woodard, English eeducationalist (d. 1891)

• March 30 – Robert Bunsen, German chemist and inventor (d. 1899)

• May 11

• *Chang and Eng Bunker, Siamese twins and sideshow performers

• *Jean-Jacques Challet-Venel, member of the Swiss Federal Council (d. 1893)

• June 14 – Harriet Beecher Stowe, American author (d. 1896)

• June 17 – Jón Sigurðsson, the leader of the 19th century Icelandic independence movement. (d. 1879)

July–December

• July 18 – William Makepeace Thackeray, British novelist (d. 1863)

• August 31 – Theophile Gautier, French writer (d. 1872)

• September 19 – Orson Pratt, American religious leader (d. 1881)

• October 22 – Franz Liszt, Hungarian composer and pianist (d. 1886)

• October 25 – Évariste Galois, French mathematician (d. 1832)

• October 27 – Stevens Thomson Mason, first governor of Michigan (d. 1843)

• November 21

• *Zeng Guofan, Chinese official and military leader (d. 1872)

• *Ludwig Preiss, Botanical collector (d. 1883)

• November 24 – Ulrich Ochsenbein, Swiss Federal Councilor (d. 1890)

• December 21 – Archibald Campbell Tait, Archbishop of Canterbury (d. 1882)

• date unknown

• *Mohammad Afzal Khan, Emir of Kabul, Emir of Kandahar (d. 1867)

Deaths

January–June

• January 10 – Marie-Joseph Chénier, French poet (b. 1764)

• February 26 – Mateo de Toro Zambrano y Ureta, Governor of Chile (b. 1727)

• March 14 – Augustus FitzRoy, 3rd Duke of Grafton, Prime Minister of the United Kingdom (b. 1735)

• April 7 – Garsevan Chavchavadze, Georgian diplomat and politician (b. 1757)

• May 4 – Nikolay Kamensky, Russian general (b. 1776)

• May 28 – Henry Dundas, 1st Viscount Melville, British minister (b. 1742)

• June 26 – Ignacio Allende, captain of the Spanish Army in Mexico

July–December

• July 30 – Miguel Hidalgo y Costilla, Mexican revolutionary (b. 1753)

• August – William Williams, signer of the United States Declaration of Independence (b. 1731)

• August 20 – Louis Antoine de Bougainville, French navigator and military commander (b. 1729)

• September – Ulrich Jasper Seetzen, explorer (b. 1767)

• September 8 – Peter Simon Pallas, German zoologist (b. 1741)

• October 11 – Johann Conrad Ammann, Swiss physician and naturalist (b. 1724)

• November 21 – Heinrich von Kleist, German writer (suicide) (b. 1777)

• November 27 – Andrew Meikle, Scottish engineer (b. 1719)