Iltutmish (1211-1236): He belonged to the Ilbari tribe and hence his dynasty was named as Ilbari dynasty. His half brothers sold him as a slave to Aibak, who made him his-son-in law by giving his daughter in marriage to him. Later Aibak appointed him as iqtadar of Gwalior. In 1211 Iltutmish defeated Aram Baksh and became Sultan. He shifted his capital from Lahore to Delhi. During the first ten years of his reign he concentrated on securing his throne from his rivals.
In the meantime, Temujin popularly known as Chengiz Khan, the leader of the Mongols, started invading Central Asia. He defeatedJalaluddin Mangabarni, the ruler of Kwarizam. Mangabarni crossed the river Indus and soughtasylum from Iltutmish. Iltutmish refused to give him shelter in order to save his empire from the onslaught of the Mongols. Fortunately for Iltutmish, Chengiz Khan retuned home without entering into India. In fact, the Mongol policy of Iltutmish saved India from the wrath of Chengiz Khan.
He marched against Bengal and Bihar and reasserted his control over them. He also annexed Sind and Multan into the Delhi Sultanate. He suppressed the Rajput revolts and recovered Ranthampur, Jalor, Ajmir and Gwalior. He led an expedition against the Paramaras of Malwa but it was not successful. Iltutmish was a great statesman. He received the mansur, the letter of recognition, from the Abbasid Caliph in 1229 by which he became the legal sovereign ruler of India. Later he nominated his daughter Raziya as his successor. Thus the hereditary succession to Delhi Sultanate was initiated by Iltutmish.
Contribution to India: He completed the construction of Qutub Minar which was started by his father in law and first sultan of Slave Dynasty Qutb-ud-din Aibak. In 1230 AD, he built the water reservoir Hauz-i-Shamsi in Mehrauli. He established the capital of Slave Dynasty in Delhi which was earlier in Lahore.
He patronized many scholars and a number Sufi saints came to India during his reign. Minhaj-us-Siraj, Taj-ud-din., Nizam-ul-mulk Muhammad Janaidi, Malik Qutb-ud-din Hasan and Fakhrul-Mulk Isami were his contemporary scholars who added grandeur to his court. Apart from completing the construction of Qutb Minar at Delhi, the tallest stone tower in India (238 ft.), he built a magnificent mosque at Ajmir.
He introduced the Arabic coinage into India and the silver tanka weighing 175 grams became a standard coin in medieval India. The silver tanka remained the basis of the modern rupee. Iltutmish had also created a new class of ruling elite of forty powerful military leaders, the Forty.
Death of Iltutmish: He ruled the Slave Dynasty till his death in 1236 AD. After death of Iltutmish his son Ruknuddin Firuz Shah became the sultan but within a short span he abandoned the throne. Razia Sultan became the sultan of Slave Dynasty in 1236 AD.