The 1815 Battle of Waterloo was a pivotal moment in European history. The continent was on the verge of all out war once again just a year after having finally defeated France in the war of the Sixth Coalition. Napoleon had returned from his exile on the island of Elba and immediately overthrown the monarchy and resumed power.
This return in March 1815 set off what is now know as the Hundred Days war. With the return of Napoleon, the European powers immediately declared war. Each of the four major powers (Britain, Austria, Prussia and Russia) of the Seventh Coalition pledged to field at least 150,000 men to end Napoleons rule for good.
Notably, this was more than the British could muster, due to their smaller standing army. In addition, many of their seasoned, veteran troops were still in the Americas finishing the battles of the War of 1812. Thus, Britain had to pay their allies subsidies to make up the difference in fighting power.
The Combatants of the Battle of Waterloo
Napoleon immediately began to muster his troops for another war. Hundreds of thousands were conscripted, though most did not have time to become fully formed units. By early to mid June, Napoleon had about 200,000 troops at his disposal. He was thus left with a choice, to attack or defend?
With his enemies superior numerical advantage, Napoleon sought an early blow to potentially knockout one or more powers. This could potentially lead the coalition to the bargaining table where Napoleon could sue for peace and remain as the ruler. The allies were slow to muster and did not attack which gave Napoleon critical time to make preparations.
In the subsequent Waterloo Campaign, Napoleon fought against two coalition armies. One Anglo-allied army totaled ~68,000 troops. This consisted of ~25,000 British, ~17,000 Dutch & Belgians, ~11,000 from Hanover, ~6,000 from Brunswick, ~6,000 from the Kings German Legion and ~3,000 from Nassau. The other army was Prussian and consisted of ~45,000 troops. The attacking French had ~72,000 troops.
At the subsequent Battle of Waterloo on June 18th, Napoleon was defeated. The Anglo allies troops held out long enough for the Prussian troops to arrive and turn the tide of the battle. Had Napoleon won, Europe could have turned out very differently.
Four days after the battle, Napoleon abdicated the throne once again. He had failed to secure political support for further military action and saw the writing on the wall. He was exiled this time to an island in the south Atlantic called Saint Helena where he would die 6 years laeter..