Yadav
The Yadavs, mentioned in the Mahabharata, were Pastoral-Kshatriyas among whom Krishna was brought up. The Gopas, whom Krishna had offered to Duryodhana to fight in his support when he himself joined Arjuna's side, were no other than the Yadavs themselves, who were also the Ahirs. In the Mahabharata it is mentioned that when the Yadavas (belonging to the Abhira group) abandoned Dwaraka and Gujarat after the death of Krishna and retreated northwards under Arjuna's leadership, they were attacked and broken up.