Masum Khan a zamindar of East Bengal. He was the son and successor of musa khan Masnad-i-Ala, the ruler of the Bhati. After the fall and surrender of Musa Khan to the Mughals (1611) he along with his family members were kept in strict surveillance and restraints at Jahangirnagar. Masum Khan was then a boy of seven. Musa Khan, along with other zamindars, was restored to liberty in 1618 by Mughal viceroy ibrahim khan fath-i-jang. After the death of Musa Khan in April 1623, Ibrahim Khan Fath-i-Jang chose his eldest son Masum Khan, a youth of 18 or 19, as successor of his estate, and treated him with extreme kindness.
Masum Khan as a loyal zamindar served in command of the ships in the siege of Hughli (1632) by the Mughal army against the Portuguese. On the eve of the siege, he had advanced from Sripur (south of Dhaka) with a gigantic fleet of war-boats to Sankrail (16 kilometers below Kolkata) and closed the channel of the Ganges. His fleet threw a bridge of boats across the Ganges at the narrow straits. The actual attack on Hughli was kept suspended till the arrival of imperial flotilla under Khawja Sher and the fleet of war-boats of the loyal zamindars of East Bengal led by Masum Khan. In the Padshahnama, Masum Khan is included among the chief officers who took part in the Mughal invasion of Assam in 1636 AD. [Muazzam Hussain Khan]