The history of the Crimean peninsula is fascinating and a microcosm of the conflict between Western Europe, Eastern Europe, and the near east.
First of all let’s take a few minutes to look at the big picture, as you can see by the map above, the Crimea dominates the Black Sea, control of the Crimea, gives you control of the Black Sea.
Here is a map of the Crimea, so you have an idea where things are…
Now on to the history…
I won’t go into the pre-history, I will start in the early Iron Age (approximately the 8th Century B.C.), most of Crimea had been settled by Scythians, with the exception of southern Crimea where the Tauri (Cimmerians) lived, possibly evicted from the rest of Crimea by the Scythians.
By the 7th Century B.C. Greeks had established colonies in Crimea, allying themselves with the Tauri, against the Scythians, by the 4th Century B.C., the Greek colonies had grown strong enough to form a Kingdom (the Kingdom of Cimmerian Bosporus), this Kingdom was eventually ruled by Pontus, regained their independence, and then became a Roman client Kingdom. By the mid 3rd Century, Rome had abandoned the Crimea.
After the end of quasi-Roman rule, the Crimea was invaded and/or occupied by a succession of invaders including the Goths (250), the Huns (376), the Bulgars (4th thru 8th Century), and the Khazars (8th Century).
In the mid 10th Century, Sviatoslav I of Kiev conquered the eastern part of the Crimea while the southern end was part of the Byzantine Empire (Cherson Theme). In 988, Vladimir the Great conquered what is now Sevastopol (an impressive Eastern Orthodox cathedral marks the spot of that historical event.
During the Summer of 1238, Batu Khan (grandson of Genghis Khan) devastated the Crimea and occupied the area (with the exception of some Venetian and Republic of Genoa colonial cities) until 1441.
As a side note, during the Siege of Kaffa  (Feodosiya) by the Golden Horde, many historians believe that the first documented use of biological warfare, when Mongols who died of the plague were catapulted over the walls, possibly spreading the plague to Western Europe.
In 1441, Haci I Giray (another descendent of Genghis Khan) formed the Crimea Khanate from the remnants of the Golden Horde (destroyed by Tamerlane, believe it or not, another Genghis Khan descendent). The Crimea Khanate lasted (primarily as a tributary kingdom) until 1783 when Russia annexed the entire area. It was during the time of the Crimean Khanate that thousands of Ukrainians and Russians were captured and sold as slaves in Kaffa (numbering in the tens of thousands a year from 1450 until at least 1647.
The Crimea remained under Russian authority from 1783 until 1954, when for administrative and political pandering reasons the area was transferred from the Russian Soviet Federated Socialist Republic to the Ukrainian SSR.
After the breakup of the USSR, Crimea remained part of the Ukraine, until the recent annexation by Russia.
I apologize for the tardiness, and for the very quick and incompleteness of this missive, although it does give one a better feel for the chaotic nature of the history of the Crimea.