Births on January 1

Achille Guenée, French lawyer and entomologist (d. 1880)

Achille Guenée (sometimes M.A. Guenée; 1 January 1809 – 30 December 1880) was a French lawyer and entomologist.

16 Jan

Battle of Corunna
Peninsular War: The British defeat the French at the Battle of La Coruña.
10 Apr

War of the Fifth Coalition
Napoleonic Wars: The War of the Fifth Coalition begins when forces of the Austrian Empire invade Bavaria.
20 Apr

Battle of Abensberg
Two Austrian army corps in Bavaria are defeated by a First French Empire army led by Napoleon at the Battle of Abensberg on the second day of a four-day campaign that ended in a French victory.
17 May

Papal States
Emperor Napoleon I orders the annexation of the Papal States to the French Empire.
5 Jul

Battle of Wagram
The largest battle of the Napoleonic Wars, the Battle of Wagram is fought between the French and Austrian Empires.