Parvatas Kingdom refers to the territory of a tribe known as Parvatas (Mountaineers), mentioned in the epic Mahabharata. Most of the descriptions of Parvata kingdom in the epic refer to a mountainous country in the Himalayas. Parvatas are people from Nepal. There used to be a nation named Parvata in Nepal until it was unified with Nepal. Tribes belonging to other mountainous regions in the north west, west and the east of the Indo-Gangetic Plain were also known as Parvatas, when used as a collective name. Parvatas took part in the Kurukshetra War. The epic also mentions a sage named Parvata who was a companion of sage Narada.
References
Parvata Kingdom Wikipedia(Text) CC BY-SA