Napoleon's reign refers to the period during which Napoleon Bonaparte ruled France and much of Europe from 1799 to 1815, marked by his rise to power as First Consul, his declaration as Emperor, and his military conquests across the continent. This era brought significant changes in political structures, legal reforms, and social norms while also maintaining some continuity from the revolutionary ideals of liberty and equality. Napoleon's reign ultimately reshaped European politics and society, leading to both the spread of nationalism and the eventual coalition against him.