In 1853, Russia invaded the Danubian Principalities, just west of its empire on the Black Sea. Britain and France responded by allying with the Ottoman Empire and declaring war on Russia. Much of the fighting over the next three years would take place in Crimea, as allied forces tried to break Russia’s grip on the city of Sevastopol. The Crimean War would leave about 375,000 allied troops and anywhere from 143,000 to 522,000 Russian troops dead—mostly from disease—and devastate the Crimean Peninsula.
During the Russian Civil War, Crimea would become a stronghold for the anti-Bolshevik White Army and its sympathizers. But by 1920, the White Army was evacuating and the Bolsheviks stormed the peninsula. The communists distributed questionnaires and, foreshadowing Nazi tactics that would one day be used against them, used the answers to divide the population into those to be killed, imprisoned, or saved. More than 50,000 people, most of them civilians, were slaughtered over about six weeks.