The Crimean War was a conflict between Russia and the alliance of France, the Ottoman Empire, the United Kingdom and the Kingdom of Sardinia. Around 700,000 Russian troops participated, with 400,000 French, 300,000 Ottoman, 250,000 British and 18,000 Sardinian soldiers opposing them.
The primary causes of the war included Russia's desire to expand south and secure a route to the sea that, at the time, led through Ottoman territory. Under the guise of acting to protect Christians in Muslim lands, Russia launched an invasion of Ottoman territory. The British were quick to support the Turks against Russia, and Emperor Napoleon III saw the conflict as a way to position himself as a protector of Christianity. Russia found early victories against the Ottomans, but soon the superior naval forces of the United Kingdom and France drove Russian forces back. Russia signed a peace treaty in 1856 that maintained Turkish independence until World War I.
One of the most famous engagements of the war was a cavalry charge against entrenched artillery during the Battle of Balaclava in 1854. Alfred Lord Tennyson immortalized the doomed attack in a poem, "The Charge of the Light Brigade." While nearly 300 riders were struck down in the course of the charge, their conspicuous bravery set the Russian heavy cavalry into full retreat and helped turn the tide of the battle.