Anguttara Nikaya
During vedic era Viratnagar was the capital of Matsya Kingdom (300-700 BC), which was one of the "solasa" (sixteen) Mahajanapadas (great kingdoms) during vedic era as described in the hindu epic Mahabharta and 6th BCE Buddhist text "Anguttara Nikaya". Matsya kingdom had Kuru and Surasena mahajanapadas to its north and east respectively.