His public career began in 1795: he was twenty-six and had twenty-six years ahead of him. His successful Italian campaign of 1796-97 and his great military reputation enabled him after his abortive descent on Egypt in 1798-99 to abolish the Directory and assume the powers of King (nominally " First Consul ") and a few years later Emperor. For eight years everything went very well with him. He forced a general peace on France's enemies in 1802: France kept the Austrian Netherlands and the left bank of the Rhine and was suzerain of vassal states Holland and Switzerland, and completed several reforms foreshadowed by the Jacobins, including the codification of the law (the Code Napolion). When he goaded England into war again in 1803 he was perhaps forestalling the inevitable, but English money, English mobility of transport, the English blockade, and finally an English general were to ruin him. He beat England's continental allies decisively in 1805-07, and though his scheme of invading England had failed, he was in 1807 at the pinnacle of success, with Germany and Poland added to the French empire (which now included Italy) and Russia in alliance.

But the next eight years saw him stumbling towards the pit. In order to destroy one source of England's wealth by cutting off her continental trade, he invaded Portugal and Spain (1807-13) and Russia (1812); he would bring the whole Continent under control. The geographical difficulties and the national resistance of these countries (not only their governments and mercenary armies, but their civilians) gave the opportunity for Germany and Austria to fall on him in 1813. After his exile in 1814 he returned, reigned again for the Hundred Days, and met his match in Wellington at Waterloo (1815).