Pursuant to the death of Hajji Giray (1466), there was a long period of turmoil with the struggles for the throne that burst out among his sons. The rivals that were defeated would run away to the steppe lands out of the peninsula or take shelter in Kefe; and thus they would continue their struggles thereof. The Genoese people in Kefe took side with some party or the other in order to reinforce their conditions and they played an important role in these struggles. The main struggle was between Nurdevlet and Mengli Giray. Mengli Giray was defeated and he took shelter in Kefe. Then, he ascended the throne of the Crimea again in the year of 1468 through the support of the bey of Sirin tribe and the Genoese people.
Fatih Sultan Mehmet benefited from the struggles for the throne that continued in the Crimea and the intervention of the Genoese people into this region through various means. He sent Gedik Ahmet Pasha with a strong naval fleet immediately to Crimea (1475). He thus captured all the ports located on the coasts of Kefe and the Crimea that pertained to the Genoese people. Mengli Giray that was saved from prison by Gedik Ahmet Pasha could take the sovereignty from Nurdevlet who was the friend of Genoese State. Then, he was submissive to the Ottoman sultan. After one month and a half, he wrote a letter to the ruler and confirmed his submission in this letter. Accordingly, the Khan had accepted the friends of the ruler as his friend and the enemies of the ruler as his enemies and his submission to the ruler.
In the year of 1476, Seyyid Ahmed who was the ruler of the Golden Horde State invaded the Crimea. Upon the threat of Ottoman ruler, the Golden Horde khan left one of his governors named as Canibek and returned to his country. Upon this event, Nurdevlet was able to establish dominion in the Crimean Khanate under the Ottoman protection. Mengli Giray was brought to Istanbul and arrested there. After a while, Eminek who was the chief of the Crimean tribal aristocracy caused some turmoil against Nurdevlet Khan. Then, he provided the enthronement of Mengli Giray as the first khan of the Crimean Khanate that was sent from Istanbul by the ruler. The events in relation with the enthronement of Mengli Giray in the year of 1475 and the events that took place in the year of 1478 were always confused within the Ottoman chronicles. In the course of this third domination of Mengli Giray (1478-1514), the Crimean Khanate had a strong establishment and organisation. The Ottoman protection provided the union of authorities in the khanate and it guaranteed the existence of the khanate against the attempts for the integration of the last Golden Horde khans and the expansionist policy of Moscow. The khanate had participated in the military expedition towards Akkerman organised by Bayezid II for the first time in the year of 1484 and it started to its policy of cooperation with the Ottomans in the west.
From that date on, the Crimea was united with the Ottoman Empire. However, it has a privileged status much different from the other Ottoman provinces. The Crimean Khan had maintained their prayers and coins by inheritance from their ancestors and he was treated like a little brother of the Ottoman Ruler. This union increased the power of the Crimea and therefore, the power of the Ottoman State. Finally, Mengli Giray who had been the father-in-law of Yavuz Selim had provided assistance for the enthronement of Selim in the throne of the Ottoman State.