Battle of Waterloo (1815)

Waterloo on 18 June 1815 delivered a final, unrecoverable blow to Napoleon that the Battle of Leipzig in 1813 only temporarily achieved, halving the French Empire within a month. Wellington and Blucher's defeat ended 23 years of European warfare, dissolved the Napoleonic Empire, and established the Concert of Europe, which maintained great-power peace for nearly a century. Napoleon's exile to St Helena permanently ended French imperial expansion, and the battlefield saw over 25,000 French casualties, reshaping European borders in ways that endured until World War I.