You just asked the question that people have been asking for about two hundred and fourteen years. Infact, it taps into a question that historians have had since Thucydides, maybe even Herodotus.

Why do leaders go to war? Why do they sacrifice tens of thousands, maybe even millions of lives to their ambition? If you ever come up with a good answer for that first one, write a book about it! But in terms of Napoleon, I have some inklings.

Biographical studies are the most use here, but Napoleon's own writings cannot be dismissed either. He has clear, fluid prose, but I've only ever read excerpts; alongside this, opinions on Napoleon severely curb what the author believes his motivations to be. Robert Harvey lauds his abilities, and then calls him a 'monster'. John Robert Elting, in giving a superb treatise on the Grand Armee, views him as a brilliant military man but an incompetent adventurer strategically and politically. Look at David Chandler or David Gates for a more balanced view of him, and Philip Dwyer's very recent 'Napoleon: The Path to Power' for quite a positive view of him.

So it certainly is an interesting question. Historical fiction likes to depict him as having an immense chip on his shoulder; short, fiery, intelligent, with a provincial accent. Unfortunately, this doesn't really account for all that much - he wasn't overly short, and while he was certainly considered provincial, so were Gascons, Bretons and men from Nice, like Marshal Massena. In truth, the 'chip on his shoulder' idea might have some early psychological motivation buried within it, but it can't be pushed far past his Italian campaign.

Honestly? I think his motivations changed. He led the French in Northern Italy to become rich and famous, and he led them into Egypt to become an adventurer. But why did he cease power? How do you go from loyally serving a country, to toppling it's government and remaking it under your will? The best answer is 'haven't the foggiest', but that's also a fucking cop-out, if the mods will excuse my thoroughly unacademic language. We don't know, but we can speculate. I believe it was a mixture of frustration and opportunism. Through his defence of the Directory in 1795, he came to see them as weak. Through their perceived abandonment of him in Egypt, he came to see them as incompetent and treacherous. Through his arrival back in France, he came to see that he could never well take and control France.

Think on this, if you had been betrayed by your Government, if you knew you could remove it, and you earnestly believed you could do a better job, would you not? Maybe, but Napoleon was first and foremost an opportunist, and it is present in his tactics, in his strategies, and in his politics. So when he undertook the coup in 1799, we get some sense of the 'why'.

But then comes the campaigns. The wars. The big, ground-shaking efforts that saw General Mack cornered in the centre of Germany, that saw the combined might of Russia and Austria destroyed at Austerlitz, that saw the largest army ever brought together murdered by starvation, frost and Cossacks in the winter of 1812 and 1813. I think the same answers we used for the taking of power in 1799 cease to be useful from then on. In foreign politics, Napoleon needs war. He needs it in 1800 to secure his power base and legitimacy. He needs it in 1803 to keep his economy rolling on the spoils of warfare. He needs war to continue his reign, to keep his power base happy, and he is ALSO an opportunist. He invades Spain despite there being very little value in it as a prize, he forms the Confederation of the Rhine as a psuedo-French satellite, he brutally dismembers Prussia despite entreaties from Talleyrand, he deals in humiliation and political bullying. Twice, this isn't the case - The Peace of Amiens in 1803, and the Treaty of Tilsit in 1807. Honestly, I think my belief in Napoleon as an opportunist is a bit shaky here; but it can be argued that both of these treaties were attempts to consolidate his power after quite remarkable victories.

But he pushed too far; he pushed the four great powers too far, he pushed his economy too far, his pushed his people too far, and he pushed his Marshals too far. Napoleon was forced to abdicate because of a thousand factors, but I believe that a fundamental cause was that opportunism inside him - the urge to reach out and take something if it was there.

I'm not a Napoleonic scholar; I like fighting, battlefield tactics and the physical aspects of warfare, and that means I have a soft spot in my heart for the daring Corsican. He was incredible. And what motivates an incredible man? Honestly, I don't know. This is a bad answer. But I earnestly believe that the rather villainous response 'because I could' suits Napoleone di Buonaparte quite well.

The so called Napoleonic wars:

1803: Treaty of Amiens breaks down, both Napoleon and Britain should share blame, but Britain's war party put forward conditions that they knew Napoleon wouldn't agree to, and didn't adhere to the others.

1805: Austria and Russia joined Britain's coalition against France, declaring war first.

1806: Austria and Russia were defeated, but Russia was still in the contest and Prussia wanted in, they declared war.

1807: Russia last still standing on land, they were finally defeated for good.

1807: Napoleon invades Portugal to enforce continental system against Britain.

1808: Spain rebels against French rule when Napoleon deposed the Bourbons in favor of his brother Joseph. In 1806 Napoleon found correspondence linking their Prime Minister to the Prussians and promised to betray France if Prussia was to win a battle. The monarchy itself was weak and corrupt, protecting the inquisition and nobility in favor of the people.

1809: Austria invades Bavaria, France's ally. With Spanish resistance keeping the Grand Armee to the west, they smelled blood and wanted revenge.

1812: France invades Russia to enforce continental blockade against Britian, which Alexander had agreed to in 1807 in lieu of territorial concessions, and to protect Duchy of Warsaw, France's ally who Alexander was bullying and mobilizing forces against. He smelled blood with Napoleon embroiled in the Spanish Peninsula.

1813: Prussia and Austria declare war on France. They sensed weakness after the failed campaign in Russia.

1815: Prussia, Austria, Russia and Great Britain declare Napoleon an outlaw and mobilized against him first. Upon returning to the throne from Elba, he promised to adhere to France's pre-Revolutionary boundaries. They didn't care.

So as you can see, Napoleon started fewer wars than his enemies and usually his motivation was to either defend France's territory (imperial or otherwise) or to bring Britain to the peace table.