Short answers, pulled from the story.
Hacı I Giray arrived in Crimea from exile in Lithuania during the early 15th century. He fought for independence against the Golden Horde from 1420 until 1441 when he secured his position as ruler.
Gedik Ahmet Pasha led Ottoman forces into the Crimean peninsula in 1475 to conquer the Genoese colonies at Caffa and Soldaia. This military campaign forced Meñli I Giray to accept suzerainty over the steppes while the Ottomans annexed the coastal regions directly.
Historians estimate that about 2 million slaves were exported from Russia and Poland-Lithuania between 1500 and 1700. A major raid in 1769 resulted in the capture of 20,000 Russian and Ruthenian people.
Catherine II intervened on the 8th of April 1783 to annex the whole peninsula as Taurida Oblast violating the Treaty of Küçük Kaynarca from 1774. The last Crimean khan Şahin Giray took refuge in the Ottoman Empire where he was eventually executed on Rhodes for betrayal.