It began with the Continental System. Napoleon was angry with England, so he told all of Europe to cut off trade with them. However, Europe didn't want that so his plan failed.
Then, Napoleon went on to invade Russia. The Russians knew France was coming, so they left Moscow and destroyed all of its resources. Napoleon left with 600,000 soldiers and came back with none.
The cold killed 580,000 of the men, and the rest died on the way back. Napoleon abandoned his men. France was not happy about this at all.
In 1813, the Quadruple Alliance defeated Napoleon at the Battle of The Nations. In 1814, Napoleon is abdicated and exiled to Elba.
However, he comes back, loses the Battle of Waterloo and is exiled again to St. Helena where he dies.