March 2, 1811
A royalist fleet defeats a small flotilla of revolutionary ships in the Battle of San Nicolás on the River Plate.
The Battle of San Nicolás was a naval engagement on 2 March 1811 on the Paraná River between the Spanish royalists from Montevideo, and the first flotilla created by the revolutionary government of Buenos Aires. It was the first engagement between the two fleets in the River Plate region since the revolution. It was a royalist victory.
March 9, 1811
Paraguayan forces defeat Manuel Belgrano at the Battle of Tacuarí.
The Battle of Tacuari was a battle in Southern Paraguay between revolutionary forces under the command of General Manuel Belgrano, member of the Primera Junta government of Argentina, and Paraguayan troops under colonel Manuel Atanasio Cabañas, at the time at the service of the royalists.
Births
April 5, 1811
Jules Dupré, French painter, was one of the chief members of the Barbizon school of landscape painters. If Corot stands for the lyric and Rousseau for the epic aspect of the poetry of nature, Dupré is the exponent of her tragic and dramatic aspects.

May 11, 1811
Chang and Eng Bunker were the conjoined twin brothers whose condition and birthplace became the basis for the term "Siamese twins".

July 18, 1811
William Makepeace Thackeray was an English novelist of the 19th century. He was famous for his satirical works, particularly "Vanity Fair", a panoramic portrait of English society.

August 3, 1811
Elisha Graves Otis was an American industrialist, founder of the Otis Elevator Company, and inventor of a safety device that prevents elevators from falling if the hoisting cable fails. He worked on this device while living in Yonkers, New York in 1852, and had a finished product in 1854.

August 30, 1811
Pierre Jules Théophile Gautier was a French poet, dramatist, novelist, journalist, art critic and literary critic. While Gautier was an ardent defender of Romanticism, his work is difficult to classify and remains a point of reference for many subsequent literary traditions such as Parnassianism, Symbolism, Decadence and Modernism. He was widely esteemed by writers as diverse as Balzac, Baudelaire, the Goncourt brothers, Flaubert, Proust and Oscar Wilde.

October 22, 1811
Franz Liszt was a 19th-century Hungarian composer, pianist, conductor, and teacher.