The Crimean War (1853–1856) was one of the most significant conflicts of the nineteenth century and marked a turning point in European diplomacy, military organization, and the balance of power. It was fought primarily between the Russian Empire on one side and an alliance of the Ottoman Empire, Britain, France, and later the Kingdom of Sardinia on the other. The war was centered in the Crimean Peninsula but also involved military operations in the Balkans, the Baltic Sea, the Caucasus, and the Black Sea. It exposed the weaknesses of the Russian Empire while reshaping international relations and influencing Russia's future role in global affairs. The immediate cause of the Crimean War was a dispute over the protection of Christian holy places in Palestine, then under Ottoman control. France supported the rights of Roman Catholics, while Russia claimed to protect Orthodox Christians within the Ottoman Empire. Behind this religious issue lay deeper political and strategic interests. Russia sought greater influence over the declining Ottoman Empire and aimed to expand its access to the Mediterranean through the Black Sea. Britain and France viewed Russian expansion as a threat to the European balance of power and to their own strategic and commercial interests, especially the security of trade routes to Asia. The conflict began when Russia occupied the Danubian Principalities of Moldavia and Wallachia in 1853. The Ottoman Empire declared war, and Britain and France entered