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.
Al-Ashraf Qansuh Al-Ghuri
On the succession, however, of Selim I to the throne of Ottoman Sultanate, things took a very different turn. Not only had the attitude of Shah Ismail I become more threatening, but Sultan Selim I himself was more of the warrior than his father. Selim I set out against him, and the Battle of Chaldiran was fought near Tabriz on August 23, 1514. The fanaticism of the Sufis, which led even to their women joining in the combat, failed against the cavalry and artillery of the Turks, and Ismail after a disastrous defeat fled and escaped. Selim I, his provisions failing, returned westward and spent the winter at Amasia. In the spring taking the field again, he attacked the bey of Dulkadirids who as Egypt's vassal had stood aloof, and sent his head with tidings of the victory to Mamluk Sultan Al-Ashraf Qansuh al-Ghawri. Selim I later overran Diyarbakır and Iraq, taking Roha, Nisibin, Mosul and other cities. Secure now against Shah Ismail I, a larger project dawned upon Selim I; it was the conquest of Egypt, and the fact that the invasion must be made from Syria. With no anxieties toward the North, he could now safely make the advance, and so in the spring of 1516 CE he drew together for this end a great and well-appointed army; and with the view of deceiving Egypt, represented his object to be the further pursuit of Shah Ismail I.