Rajapura or Rajapuram was the capital of Kamboja Kingdom of the epic times as evidenced by epic Mahabharata

Mahabharata

The Mahabharata is one of the two major Sanskrit epics of ancient India and Nepal, the other being the Ramayana. The epic is part of itihasa....

. Karna

Karna

Karna or Radheya is one of the central characters in the epic Mahābhārata, from ancient India. He was the King of Anga...

 had led a war expedition against the Kamboj and some other tribes of the Uttarapatha

Uttarapatha

Ancient Buddhist and Hindu texts use Uttarapatha as the name of the northern part of Jambudvipa, one of the "continents" in Hindu mythology.The name is derived from the Sanskrit terms uttara, for north, and patha, for road...

 a little time before the Kurukshetra war

Kurukshetra war

According to the Indian epic poem Mahābhārata, a dynastic succession struggle between two groups of cousins of an Indo-Aryan kingdom called Kuru, the Kauravas and Pandavas, for the throne of Hastinapura resulted in the Kurukshetra War in which a number of ancient kingdoms participated as allies of...

 i.e. Karana Rajapuram gatva Kamboja Nirjitastvaya . Chinese pilgrim Hiuen Tsang [602/603? - 664 CE], who had traveled to India (~629-645 CE), names this city as Ho-b-she-pu-lo which has been identified as Rajapura of Sanskrit tradition by Watters and others .