What is the story behind he met his Waterloo?

In February, 1815, Napoleon left the island of Elba with the goal of retaking France. He did so in just a matter of weeks, causing King Louis XVIII to flee. Great Britain, Prussia, Austria, and Russia joined together to remove the threat posed by Napoleon. Great Britain and Prussia had their armies in the field by May while Austria and Russia had mobilized and were on the move.
Napoleon intended to defeat the British and the Prussians before Austria and Russia could arrive. He moved his forces toward Waterloo. The Duke of Wellington was awaiting the arrival of the Prussians under Marshal Bleucher von Wahlstatt at Waterloo.
On Sunday, June 18, 1815 Wellington adopted a strong defense to deal with Napoleon's brilliance in the offense. When Napoleon attacked in the early afternoon Wellington had his troops well beyond the range of the French cannons, and counterattacked the French infantry. While Napoleon's force regrouped, the Prussians arrived and turned the tide, causing Napoleon's defeat at Waterloo. On June 22, 1815 Napoleon once again abdicated his throne and never returned to power.
The phrase "met his Waterloo," means to meet one's end or to be defeated.