In 1811, Napoleon's empire and its allies had over 44 million subjects and covered most of Europe.
But after being defeated in 1813 and 1814 by the Sixth Coalition, which included Austria, Prussia, Russia, Britain, Portugal, Sweden, Spain and other German states, Napoleon was forced to abdicate and exiled to the island of Elba.
The First French Empire was dissolved, and the Bourbon monarchy restored, but in February 1815 Napoleon escaped from his exile and returned to France to take command once again.
The culmination of his triumphant return, known as the Hundred Days, was the Battle of Waterloo in June 1815, which finally brought his downfall at the hands of the British allied forces and the Prussians.
The three Waterloo generals (l-r): Napoleon, Arthur Wellesley, Duke of Wellington, and Gebhard Leberecht von Blücher, the Prussian commander. Images: Wikimedia Commons
La Haye Sainte
Brendan Simms, Professor of the History of International Relations at Cambridge University, has just published a book telling the story of a small group of Germans that ended up being decisive in the final outcome of the battle.
"The Long Afternoon" depicts the defence of La Haye Sainte, a farmhouse located just in front of Wellington's front line.
Simms told the Local that "La Haye Sainte features in most detailed accounts of the battle, but not enough because it was absolutely crucial in the outcome."
The important task of defending this ground in order to protect Wellington's main line was given to the King's German Legion, a group of around 400 men from Hanover following British orders, as King George III was also Elector (prince) of Hanover before the city was taken by Napoleon in 1803.
Men of the King's German Legion. Image: Wikimedia Commons
The Prussian army had been defeated a few days earlier nearby in Ligny, but had regrouped and was marching to support Wellington's forces.
The King's German Legion bravely managed to hold their positions for most of the day until their ammunition ran out, and by the time they eventually had to retreat from the farmhouse, the Prussian army had arrived in support, and the allied forces were able to counter attack to victory.
The narrative of the Napoleonic wars is often dominated by the victorious generals, like Nelson at Trafalgar and Wellington at Waterloo, neglecting the rank-and-file soldiers who did the fighting.
In a letter in 1813, Wellington described these men as "the scum of the earth", but they are very much the focus of Simms' detailed account.
"It is true that not much has been written about the ordinary soldiers, but luckily the King's German Legion awarded medals to them, and these accounts were useful in my research," he said.
The Storming of La Haye Sainte, painted by Richard Knötel. Image: Wikimedia Commons
La Haye Sainte represents an example of how a small group of Germans played a decisive role in what is often considered a great British victory.
The period after Waterloo was one of cooperation between Britain and the German states, which Simms described as "Anglo-German symbiosis".
"The link between the British monarchy and Hanover ended in 1837 (when Queen Victoria took the throne), but It wasn't until the late 1890s that Anglo-German relations soured," he said.
The farmhouse where the brave defence took place still stands today, and across the road is a memorial to the King's German Legion. There is also a Waterloo column in the city of Hannover.
But it is the Battle of Leipzig of 1813, also known as the Battle of Nations, that is remembered the most in Germany.
"Leipzig is important in the German consciousness, because it is part of the narrative of liberation from Napoleon, and took place on German soil, but Waterloo should be represented more," Simms arged.
On the other hand, Waterloo plays a huge part in British collective memory, and a memorial service is to be held at St Paul's Cathedral on Thursday. A huge re-enactment is also taking place this week at the site of the battle in Belgium.
Simms said: "It is important to stress the spirit of commemoration, because Waterloo is a true lieu de memoire [place of memory] for much of Europe".
By Matty Edwards