Births on October 20

Karl Andree, German geographer and journalist (d. 1875)

Karl Andree (20 October 1808 – 10 August 1875) was a German geographer.

22 Jan

Invasion of Portugal (1807)
The Portuguese royal family arrives in Brazil after fleeing the French army's invasion of Portugal two months earlier.
6 Apr

American Fur Company
John Jacob Astor incorporates the American Fur Company, that would eventually make him America's first millionaire.
8 Apr

Pope Pius VII
The Roman Catholic Diocese of Baltimore is promoted to an archdiocese, with the founding of the dioceses of New York, Philadelphia, Boston, and Bardstown (now Louisville) by Pope Pius VII.
3 May

Sveaborg
Finnish War: Sweden loses the fortress of Sveaborg to Russia.
6 Jun

Joseph Bonaparte
Napoleon's brother, Joseph Bonaparte, is crowned King of Spain.