What to know about Crimea, the Black Sea peninsula seized by Russia from Ukraine over a decade ago Russia’s illegal seizure of the Crimean Peninsula from Ukraine in March 2014 was quick and , Crimea, autonomous republic, southern Ukraine. The republic is coterminous with the Crimean Peninsula, lying between the Black Sea and the Sea of Azov. In 2014 Russia covertly invaded and illegally annexed Crimea, a move that was denounced by the international community., It has been 11 years since Russia took control of Crimea but Moscow's invasion of Ukraine has put the peninsula back in the global spotlight. Here's what you need to know., What to know about Crimea, the Black Sea peninsula seized by Russia from Ukraine over a decade ago Russian soldiers guard a pier where two Ukrainian naval vessels are moored, in Sevastopol, on the Crimean Peninsula, March 5, 2014., While Putin says Crimea has always been Russian, the peninsula has changed hands over the centuries, having been variously administered by the Russian Empire, warring factions during WWI and the , Russia sent forces into Crimea and seized control of the peninsula after Ukraine's pro-Russian president, Viktor Yanukovych, was ousted during mass protests in February 2014..