Qutbuddin Aybak was a slave of Mu'izz al-Din, whose reign started Delhi Sultanate. On account of his lineage, his dynasty is known as the Mamluk (Slave) Dynasty.
Aybak's reign as the Sultan of Delhi lasted 4 years (1206-1210). After his death, Aram Shah assumed power in 1210, but he was assassinated by Shamsuddin Iltutmish (his nephew) in 1211.
Shamsuddin Iltumish conquered Multan and Bengal from contesting Muslim rulers, as well as Ranathambhore and Siwalik from the Hindu rulers. He also attacked, defeated and executed Taj al-Din Yildiz, who asserted his rights as heir to Mu'izz al-Din Muhammad. Iltutmish's rule lasted till 1236.
Following the death of Iltutmish, Delhi Sultanate saw a succession of weak rulers, disputing Muslim nobility, assassinations and short lived tenures.
In 1236 Sultan Iltutmish’s daughter, Raziyya, became Sultan. The chronicler of the age, Minhaj-i Siraj, recognized that she was more able and qualified than all her brothers. But he was not comfortable at having a queen as ruler. Nor were the nobles happy at her attempts to rule independently. She was removed from the throne in 1240.
In the early thirteenth century, the control of the Delhi Sultans rarely went beyond heavily fortified towns occupied by garrisons. The Sultans seldom controlled the hinterland of the cities and were therefore dependent upon trade, tribute or plunder for supplies. Its expansion occurred during the reigns of Ghiyasuddin Balban, Alauddin Khalji and Muhammad Tughluq.
Power shifted from Rukn-ud-din Firuz to Raziyya Sultan and others, until Ghiyasuddin Balban came to power and ruled from 1266 to 1287.
He was succeeded by Muiz-ud-din Qaiqabad, who ordered poisoning of Nizam-ud-din and appointed Jalaluddin Khalji as the commander of Delhi Sultanate army. Khilji assassinated Muiz-ud-din Qaiqabad and assumed power, thus ending the Mamluk dynasty.
During the Mamluk dynasty, Qutbuddin Aybak initiated the construction of Qutub Minar and Quwwatu'l-Islam.