Ali Mardan Khalji a lieutenant of bakhtiyar khalji and governor of lakhnauti from 606 to 608 AH (1210-1212 AD). He belonged to the Khalji tribe of Afghanistan, came to the subcontinent, enrolled himself in the army of Bakhtiyar, and took part in the latter's Bengal expedition. He was appointed governor of the northeastern region and had Ghoraghat as his headquarters.

Ali Mardan stabbed Bakhtiyar to death in 602 AH/1206 AD and usurped power. But he was soon arrested by shiran khalji and was kept in confinement under the care of Baba Ispahani. Ali Mardan, however, managed to escape from his confinement and took shelter in Delhi. Meanwhile iwaz khalji was given the charge of the province. Ali Mardan stayed in Delhi till he was appointed governor of Bengal by Sultan Qutbuddin Aibak. On his arrival, Iwaz Khalji handed over the charges of the province to Ali Mardan and himself retired to his own place. In this way, after a long period of hostility Ali Mardan Khalji became the ruler of Bengal.

Ali Mardan restored political unity by subduing the partisans of Shiran Khalji. He acknowledged the suzerainty of Qutbuddin, but on his death in 1210 AD, Ali Mardan declared independence in Bengal and styled himself Sultan Alauddin.

Though as sultan Ali Mardan was capable and vigorous he was, at the same time, impolite, cruel and ambitions. During the initial period of his reign he sent armies in all directions and thereby lost most of the Khalji nobles. It also appears that he got some ambitious and rival nobles exiled from Bengal by assigning them to different parts of Hindustan.

Though there is no clear evidence as to the extent of his kingdom, it seems that he re-annexed the region of Lakhnur, which Shiran Khalji had abandoned when he marched upon Devkot. During his time Bihar was also within the limits of the Lakhnauti dominion. It is also known that the Rais trembled in fear and sent him tributes and Kharaj. This indicates that probably he was bent on creating panic among the neighbouring rulers of Bang, Kamrup and Tirhut. His tyrannical policy made him unpopular and soon the discontented nobles entered into a conspiracy under the leadership of Iwaz Khalji and killed him in 1212 AD. [ABM Shamsuddin Ahmed]