The Bir King was a famous king of Birbhum before Muslim rule. Asaduzzaman Khan was an army chief who killed the Bir King and conquered Rajnagar where he established a Muslim sultanate.[1]
According to local history, in 1350 AD there were some quarrels between Laxmanawati and Subarnagram, and the ancestors of Bir King had set up a capital at Lakknur (Rajnagar). the Bir Kings were two brothers, Bir Singh and Mallar Singh. Mallarpur has named after Mallar Singh.[2]
In 1206 AD an army officer of Muhammad bin Bakhtiyar Khalji, Muhammad Shiran Khalji defeated the Bir King and conquered Rajnagar. The queen committed suicide at a nearby pond.[3]