In the following years, Abdallah Mirza was executed by Abu Sa'id Mirza, a grandson of Shah Rukh's elder brother Miran Shah, while Sultan Muhammad was killed by Abul-Qasim Babur, who himself died in 1457. The latter's successor, his eleven-year-old son Mahmud, was driven out of Herat by Ala al-Daula's son Ibrahim after a rule of only a few weeks. However, Ibrahim himself fled upon the approach of Abu Sa'id in July of that year, though the latter failed in capturing the city.