1) Napoleon crowned himself Emperor of France in 1804 after establishing himself as the dominant political and military leader. 2) He then expanded his empire across Europe through military conquests, defeating several coalitions against him. 3) However, his empire became unstable and overextended. His failed invasions of Russia in 1812 and Portugal, which sparked the Peninsular War, greatly weakened his military forces. 4) He was finally defeated by a coalition of European powers at the Battle of Waterloo in 1815, ending his attempt to reclaim power during the Hundred Days.