No historical evidence has been found about the erecting Bokainagar fort. There are two legends about the construction of the fort. According to early tradition, a
Koch tribal chieftain named 'Bokai' built the fort in the 15th century when the ancient
Kamrup kingdom was fragmenting in small kingdoms. After death of Bokai, the fort was named after him. According to another legend,
Majlis Khan Humayun, representative of
Sultan Saifuddin Firuz Shah II (1486–1489), built the fort. In 1495, the fort came under the control of
Hussain Shah and he appointed his son
Nusrat Shah as its commander. Later
Khwaja Usman fled from
Orissa after being defeated by the
Mughals and took refuge with
Isa Khan and was established as the feudal lord of Bokainagar. He rebuilt the fort and established it as a strong military base and put up a strong resistance against the Mughals from here. He was finally defeated by Islam Khan in November 1611 and the fort came under Mughal possession. Khwaja Usman's residence was in the southwestern part of the fort. Khwaja Usman built a mosque and dug a pond inside the fort. Later Subedar Chand Roy dug another pond and built a temple in the fort. == Remains ==