This fort is situated on the eastern bank of the Sone River and was founded by Dhaud Khan, a Governor of Bihar under Aurangzeb in the 17th of Palamu fort from the Cheros; and it is said that while back from this conquest he camped here and founded the town known after him. The surrounding area was also granted to him as a Jagir by the emperor. Early in the 18th century Buchanan saw it as a flourishing town with cloth and opium factories. The sarai built by Daud Khan was, perhaps really meant to be a stronghold; for it was well fortified with a battlemented wall, two large gates and a moat all around. It was called as a sarai probably to avoid jealousy of the Government. The sarai was in good condition till a few years before 1896; for the Bengal list says that the gates were regularly shut every night. Ahmad Khan, grandson of Dhaud Khan, fortified the town which was then named as Ghausipur. The town also contains an old mosque and another sarai built by Ahmad Khan, which had mud gates. In the outlying part of the town called Ahmadganj is the tomb of Ahmad Khan.
Bihar became the first state in India to have separate web page for every city and village in the state on its website www.brandbihar.com (Now www.brandbharat.com)
See the record in Limca Book of Records 2012 on Page No. 217