1812

1812 was a year marked by two major military campaigns that shaped early 19th‑century history. In Europe, Napoleon Bonaparte led the Grande Armée in the invasion of Russia, which began in June 1812. The campaign achieved a costly and indecisive outcome at the Battle of Borodino on September 7, but Moscow was occupied and the French army suffered a catastrophic retreat amid harsh winter and supply shortages, contributing to the strategic decline of Napoleon's empire by year's end.

Elsewhere, the United States entered into the War of 1812 with the British Empire, declaring war in June 1812. The conflict unfolded across multiple theaters, including engagements along the Canadian frontier and naval confrontations on the Atlantic and Great Lakes. Early campaigns produced inconclusive results, while the war continued into 1813 and 1814, influencing the development of national identities in the United States and Canada.