When the former Grand Vizier Ahmet Pasha was deposed and hanged, he was replaced by Rüstem Pasha, who had numerous enemies. One of them was Lala Mustafa, who instigated the Sultan's third son, Bayezid, then "Beylerbey" of Karaman, to raise a rebellion against his brother and heir-apparent Selim. Sokollu Mehmed mustered an army and went to Konya, where he decisively defeated Bayezid's forces in May 1559. Bayezid fled to Persia. Sokollu Mehmed remained in Asia and spent the winter negotiating with the Persian Shah regarding Bayezid's extradition. After long negotiations, the Shah handed over Bayezid and his four sons, who were subsequently executed.