The Napoleonic Wars (1803–1815) were a series of major conflicts pitting the French Empire, led by Emperor Napoleon I, against an array of European powers formed into various coalitions. They revolutionized European armies and played out on an unprecedented scale, mainly owing to the application of modern mass conscription. The wars are traditionally seen as a continuation of the Revolutionary Wars, which broke out in 1792 during the French Revolution. Initially, French power rose quickly as the armies of Napoleon conquered much of Europe. In his military career, Napoleon fought about 60 battles and lost seven, mostly at the end of his reign. The great French dominion collapsed rapidly after the disastrous Invasion of Russia in 1812. Napoleon was defeated in 1814, and then once more in 1815 at Waterloo after a brief return to power. The Allies then reversed all French gains since the Revolutionary Wars at the Congress of Vienna.