Actually the Russians are relative newcomers, having just arrived in 1783. Before that time it was controlled by the Crimean Tatars (you know, the people Stalin deported en masse in 1944). And before that, by Khazars, Bulgars, Huns, Goths, Scythians, Romans, Greeks (most significantly), and scads of others.

Either way -- the main point is (and presumably you do know this), the leased military base at Sevastopol != the Crimean peninsula.