Who he was
Napoleon rose through the chaos of the French Revolution, made his name at the siege of Toulon in 1793, and seized power in 1799. In 1804 he crowned himself Emperor.
The decisions that defined him
His campaigns relied on moving faster than his enemies expected, splitting their forces and concentrating his own at the decisive point. At Austerlitz in 1805 he deliberately weakened his right to draw the Allied armies in, then broke their centre.
His greatest mistakes were strategic. The invasion of Russia in 1812 began with an enormous army and ended with only a fraction of it returning.
How it ended
Defeated in 1814 and exiled to Elba, he escaped in 1815 for the Hundred Days, which ended at Waterloo. He died in exile on Saint Helena.