Kamsa, alternately spelt Kans, was the son of Ugrasena of the Yadava dynasty. He was half-brother of Devaki, the daughter of Devaka, Ugrasena's brother. Kamsa was the ruler of the Vrishni kingdom with its capital at
Mathura. Kamsa was informed that, he would be killed by one of Devaki’s sons. Fearing for his life, Kamsa imprisoned Devaki and her husband, Vasudeva, and murdered six of their infants. But the seventh child,
Balram, was transferred to the womb of Rohini, Vasudeva's other wife staying away from home at Nanda's house.
Lord Krishna incarnated as the seventh child of the couple. According to the divine instructions given, the baby was transferred to Gokula, on the other bank of the Yamuna. Later knowing this, Kamsa tried different sources to kill Krishna and all his attempts failed before the Lord. During the adolescent age of Krishna, he killed Kamsa.