Qutub ud din Aibak is known in history as the founder of the Slave dynasty and it is believed that the dynasty derives its name from Qutbuddin who was originally a slave. But it is also true that before accession, Qutbuddin had received the letter of manumission from his master (Mohammad Ghori) and came to accession as an independent ruler. When Mohammad Ghori died in 1206 A.D., he left no male heir to succeed him. So it was the desire of Mohammad Ghori, that Qutubuddin succeeded him and his formal accession took place on 24^th June 1206.