Which country was the opponent in the Battle of Waterloo?

The Battle of Waterloo, a pivotal moment in European history, took place in 1815 near Waterloo, which is now in Belgium. The key players were the British army, led by the Duke of Wellington, alongside allied forces, against the French army commanded by Napoleon Bonaparte. Napoleon, who had previously dominated much of Europe, had briefly regained power in France and was attempting to reassert his control. The battle was a decisive defeat for Napoleon, effectively ending his reign and marking the end of the Napoleonic Wars. Therefore, the opponent in the Battle of Waterloo was indeed France, under the leadership of Napoleon. While the Netherlands and Germany might seem plausible due to their proximity or involvement in other conflicts of the era, they were actually allied against Napoleon at Waterloo. Russia was also part of the coalition against Napoleon, but their forces weren't directly involved in the Battle of Waterloo itself.