The Khen dynasty replaced the weak rulers of the Kamata kingdom in the middle of the 15th century.

[2] In 1498, its last capital at Gosanimari was attacked by the invading army of Alauddin Husain Shah of Bengal, bringing an end to the Khen authority.

[3] Rajpat is located at 26°09′06″N 89°21′01″E / 26.1518°N 89.3502°E / 26.1518; 89.3502 The Kamtapur Fort was spread from the Dharla River in the east to Godaikhora in the west, and from Sitalabas in the north to Silduar-Soawariganj in the south.

The fort was surrounded by a horse-shoe type high earthen wall running for around 22 kilometres (14 mi) and was open only on the side where the Dharla River was there.

Various people visiting the fort in the earlier days had seen many roads, temples, ponds and other utilities.