Ghiyas ud Din was the regent of the last Shamsi sultan, Nasiruddin Mahmud. He reduced the power of the nobility and heightened the stature of the sultan. His original name was Baha Ud Din. He was an Ilbari Turk. When he was young he was captured by the Mongols, taken to Ghazni and sold to Khawaja Jamal ud-din of Basra, a Sufi. The latter then brought him to Delhi in 1232 along with other slaves, and all of them were purchased by Iltutmish. Balban belonged to the famous group of 40 Turkic slaves of Iltutmish. Ghiyas made several conquests, some of them as vizier. He routed the Mewats that harassed Delhi and reconquered Bengal, all while successfully facing the Mongol threat, a struggle that cost his son and heir's life. In spite of having only a few military achievements, Balban reformed civil and military lines that earned him a stable and prosperous government granting him the position, along with Shams ud-din Iltutmish and the later Alauddin Khalji, one of the most powerful rulers of Delhi Sultanate.