Firishta's History (Gulshan-i Ibrāhīmī) 33.1.4

33.1.4

During the reign of Alla-ood-Deen Musaood, in the year 642, he was promoted to the office of Ameer Hajib, and in the late reign of Nasir-ood-Deen Mahmood he was raised to the vizarut, which high office he filled in such a manner as to relieve the King from all anxiety and embarrassment, and on the death of his sovereign, who was also his brother-in-law, he ascended the throne not only without opposition, but even with the general consent of the nobility and people. In the reign of Shums-ood-Deen Altmish, forty of his Toorky slaves, who were in great favour, entered into a solemn covenant to support each other, and on the King's death to divide the empire among themselves. Jealousies and dissensions afterwards arose among them, and prevented this project from being carried into execution. Gheias-ood-Deen Bulbun was of this number, and as several of them had succeeded to great power in the kingdom, the first act of his reign was to rid himself of all who remained. Among these was his own nephew, the celebrated Sheer Khan.