Napoleon Bonaparte was a great leader partially because of his prowess on the battlefield that helped build a French empire, although it was short-lived; and also because of the reforms he brought to France.
Napoleon came to power after he organized the French National Guard and was subsequently appointed commander of the French army in Italy. He had been an exceptionally bright student as a young man, and had passed his examinations at the Brienne royal military academy within a single year, something not done before. Among his military accomplishments, he defeated the combined armies of Austria, Britain and Sweden at the Battle of Austerlitz and later destroyed the old Holy Roman Empire reorganizing it into the Confederation of the Rhine. On the battlefield, he personally determined the position of every cannon and every detachment of cavalry.
Domestically, Napoleon instituted a number of civil reforms, including the institution of the Code Napoleon in 1804 which assured the security of personal wealth and private property, and guaranteed all male citizens equal protection of the law. He also instituted the Bank of France and established a political bureaucracy which he himself controlled. He further signed the Concordat of 1801 with Pope Pius VII which allowed French Catholics freedom of religion, although Napoleon himself appointed bishops and church officials within France. Perhaps his most far reaching accomplishment was the establishment of the metric system, still in use in many countries.
Napoleon's primary weakness was his ambition. He once commented:
It is said that I am an ambitious man but that is not so; or at least my ambition is so closely bound to my being that they are both one and the same.
His ambition led him to declare himself "Consul for Life," and to have himself painted attired as a Roman emperor. His ambition and ruthless policies towards those who opposed him led Ludvig van Beethoven to erase his dedication of his Third Symphony to Napoleon. Beethoven reported shouted when he did so:
So he is also nothing more than an ordinary man. Now he will trample on the rights of mankind and indulge only his own ambition: from now on he will make himself superior to all others and become a tyrant.
Beethoven's words were virtually prophetic.
He was courageous and successful.
He personified the ideals of the French Revolution.
He gave promotions on the basis of performance and not social position.
He was an effective speaker.
He had a brilliant mind.