Answer:
The Crimean War
Explanation:
The Crimean War was a war that broke out around 1853, this war was fought between Russia and Britain, France and the Ottoman Empire.
With the decline of the Ottoman Empire, Russia was very interested in expanding into its territory. Britain and France aligned their interests with the Ottoman Empire and defended its territory to avoid the Russian expansion to the Ottoman territory.
But the Ottoman Empire was already declining, they were fighting wars on many fronts and began to lose control of many territories.
