Aibak was a Khitan of the Turco-Persian tradition. He was purchased as a slave by Iltutmish from the heirs of Ikhtiyar ad-Din Chust Qaba. Through his hard work and efforts, he managed to rise through the ranks, becoming the more powerful amongst the Maliks and titled Amir al-Majlis. He was given the iqta' of 28 wilayat in Sursuti by 1227. He was later stationed in Bihar.
Governor of Bengal
After the dismissal of Alauddin Jani, the Sultan appointed Aibak to be the next governor of Bengal. During his governorship, Aibak took on an expedition to South Bengal with the intention of capturing elephants. His expedition was successful, capturing a number of elephants, and dispatching several of them to the Sultan. Iltutmish was pleased with Aibak and conferred him the title of "Yughantat". Aibak married his daughter to Malik Qamaruddin Kiran Timur Khan.