Napoleon had entered the army after training as an artillery officer before the Revolution. He rose to prominence against the backdrop of crisis and war that affected the French Republic in the 1790s. As of 1795, political power had shifted again in the revolutionary government, this time to a five-man committee called the Directorate. The war against the foreign coalition, which had now grown to include Russia and the Ottoman Empire, ground on endlessly even as the economic situation in France itself kept getting worse.
Napoleon first came to the attention of the revolutionary government when he put down a royalist insurrection in Paris in 1795. He went on in 1796 and 1797 to lead French armies to major victories in Northern Italy against the Austrians. He also led an attack on Ottoman Turkish forces in Egypt in 1797, where he was initially victorious, only to have the French fleet sunk behind him by the British (he was later recalled to France, leaving behind most of his army in the process). Even in defeat, however, Napoleon proved brilliant at crafting a legend of his exploits, quickly becoming the most famous of France’s revolutionary generals thanks in large part to a propaganda campaign he helped finance.
In 1799, Napoleon was hand-picked to join a new three-man conspiracy that succeeded in seizing power in a coup d’etat; the new government was called the Consulate, its members "consuls" after the most powerful politicians in the ancient Roman Republic. Soon, it became apparent that Napoleon was dominating the other two members completely, and in 1802 he was declared (by his compliant government) Consul for Life, assuming total power. In 1804, as his forces pushed well beyond the French borders, he crowned himself (the first ever) emperor of France. He thought of himself as the spiritual heir to Alexander the Great and Julius Caesar, declaring that, a member of the “best race of the Caesars,” he was a founder of empires.
Even as he was cementing his hold on political power, Napoleon was leading the French armies to victory against the foreign coalition. He continued the existing focus on total war that had begun with the levée en masse, but he enhanced it further by paying for the wars (and new troops) with loot from his successful conquests. He ended up controlling a million soldiers by 1812, the largest armed force ever seen. From 1799 to 1802, he defeated Austrian and British forces and secured a peace treaty from both powers, one that lasted long enough for him to organize a new grand strategy to conquer not only all of continental Europe, but (he hoped), Britain as well. That treaty held until late 1805, when a new coalition of Britain, Austria, and Russia formed to oppose him.
His one major defeat during this early period was when he lost the ability to threaten Britain itself: in October of 1805, at the Battle of Trafalgar, a British fleet destroyed a larger French and allied Spanish one. The British victory was so decisive that Napoleon was forced to abandon his hope of invading Britain and had to try to indirectly weaken it instead. Even the fact that the planned invasion never came to pass did not slow his momentum, however, since the enormous army of seasoned troops he assembled for it was available to carry out conquests of states closer to home in Central Europe.
Thus, despite the setback at Trafalgar, the years of 1805 and 1806 saw stunning victories for Napoleon. In a series of major battles in 1805, Napoleon defeated first Austria and then Russia. The Austrians were forced to sign a treaty and Vienna itself was occupied by French forces for a short while, while the Russian Tsar Alexander I worked on raising a new army. The last major continental power, Prussia, went to war in 1806, but its army was no match for Napoleon, who defeated the Prussians at the Battle of Jena and then occupied Berlin. Fully 96% of the over 170,000 soldiers in the Prussian army were lost, the vast majority (about 140,000) taken prisoner by the French. In 1806, following his victories over the Austrians and Prussians, Napoleon formally dissolved the (almost exactly 1,000-years-old) Holy Roman Empire, replacing much of its territory with a newly-invented puppet state he called the Confederation of the Rhine.
After another (less successful) battle with the Russians, Napoleon negotiated an alliance with Tsar Alexander in 1807. He now controlled Europe from France to Poland, though the powerful British navy continued to dominate the seas. His empire stretched from Belgium and Holland in the north to Rome in the south, covering nearly half a million square miles and boasting a population of 44 million. In some places Napoleon simply expanded French borders and ruled directly, while in others he set up puppet states that ultimately answered to him (he generally appointed his family members as the puppet rulers). Despite setbacks discussed below, Napoleon’s forces continued to dominate continental Europe through 1813; attempts by the Prussians and, to a lesser extent, Austrians to regain the initiative always failed thanks to French military dominance.