[1] Though the time of its establishment could not be ascertained, historians believe that the river fort was built by Mir Jumla II, a Subahdar of Bengal under the Mughal Empire, to defend Dhaka and Narayanganj from pirates.

Mughals exercised a progressive rule in Bengal and were determined to protect their subjects from external forces.

Mir Jumla II was appointed as the Subahdar or governor of the then Bengal province in 1660 AD.

[2] Though archaeologists cannot trace any evidence on its date of establishment, according to historians the construction of the fort started between 1660 and 1663 AD.

Several wide and narrow loopholes allowed guns and light cannons to fire shells at the pirates.