Wikipedia
The Uttamabhadras are an ancient Indian tribe described in the Mahabharata. They lived in the Punjab. Uttamabhadras originally were people of Balkh who had entered India in Vedic times. In Vedic times, they were closely related to Kurus and the Purus. In Kurukshetra war, we also find Madras associated with the Kurus. King Shalya had taken part in the Mahabharata war, on behalf of the Kauravas. Madri, the mother of Pandava-putras Nakula and Sahadeva, was a Madra princess. Madri has also been referred to as Bahliki i.e. princess of Bahlika janapada/tribe and king Salya has been referred to as Bahlika-pungava i.e. foremost among the Bahlikas. Epic also refers to king Ashvapati of Madra, the beloved of the Paura Janapadas, who was father of Savitri. King Vyusitashva was a descendent of Puru a famous king of Rigvedic times.