Bettiah is a city in Bihar state of India. In 1244 A.D., Gangeshwar Dev, a Brahmin of Oiniwar faction settled at Jaithar in Champaran. One of his relatives, Agar Sen gained an extensive area in the rule of Emperor Jehangir and was offered the title of 'Raja' by Emperor Shah Jahan. In 1659, he was prevailing by his child Raja Guj Singh, who constructed the royal residence of the family at Bettiah. He kicked the bucket in 1694 A.D.
The royal residence stands today however fills in as commercial center because of the disregard of specialists. Because of similitude in names with Oiniwar line rulers , same Gothra and Renaming their cash-flow to same as Simraon/Sugauna its accepted that this ruler was likewise a descendent of prior decision Oiniwar Dynasty . This view additionally fortified in their connection with Naimisaranya a typical place Vidyapati alluding in his book Bhuparikrama as birthplace for Oiniwar Kings. In 1765, when the East India Company procured the Diwani Bettiah Raj held the biggest domain under its purview. It comprised of all of Champaran with the exception of a little part held by the Ram Nagar Raj.