Iltutmish, originally a slave of Qutbuddin Aibak, rose through the ranks due to his exceptional administrative and military skills and later became the greatest ruler of the Slave or Mamluk Dynasty. He consolidated the Delhi Sultanate after Aibak’s death and successfully defended it against internal revolts and external threats. Iltutmish issued the first regular currency of the sultanate and completed major architectural works such as the Qutub Minar. He also introduced the Iqta system more systematically and gained recognition from the Abbasid Caliph, which increased the legitimacy of his rule. His reign firmly established the foundations of the Delhi Sultanate.