Transformation of the Ottoman Empire
Sultan Suleiman I (r. 1520–1566) was the longest-reigning sultan in Ottoman history, but the last years of his reign were characterized by uncertainty over who would be his successor. Suleiman had three sons who could hope to succeed, Mustafa, Bayezid, and Selim. While the latter two were the children of Suleiman's wife Hurrem Sultan, the first was the son of an earlier concubine. Mustafa may have felt that his half-brothers possessed an unfair advantage over him, and thus worked to secure the favor of the military. Perhaps suspecting that Mustafa planned to dethrone him just as his own father had done to his grandfather, Suleiman acted first and in 1553 ordered that Mustafa be executed. The death of Hurrem Sultan in 1558 triggered open conflict between the two remaining candidates, and Selim ultimately emerged victorious. Suleiman further strengthened his son's position by arranging a marriage between Selim's daughter and the influential Sokollu Mehmed Pasha (Grand Vizier 1565–1579). Suleiman died in 1566, while besieging the fortress of Szigetvar in Hungary, bringing Selim to the throne.
Ottoman dynasty
The Ottoman dynasty operated under several basic premises: that the Sultan governed the empire’s entire territory, that every male member of the dynastic family was hypothetically eligible to become Sultan, and that only one person at a time could be the Sultan. Such rules were fairly standard for monarchic empires of the time. The certain processes through which men rose to the Sultanate, however, were very specific to the Ottoman Empire. To go into greater detail about these processes, the history of succession between Sultans can be divided into two eras: the period between the reign of Orhan (1323-1362), the first person to inherit the Ottoman sultanate, and the reign of Ahmed I (1603-1617); and the period following Ahmed I’s reign.