About five thousand years ago, during the Dwapara Yuga the Kings in the country of Bharat were puffed up with pride on account of wealth and started abusing the people and torturing them like demons in human form. Mother earth could no longer bear their cruelties and therefore prayed to to God to relieve her of this agony. God appeared before her and assured, ‘Oh! Mother!! I will take care of this problem. You need not have to bear this burden and agony any more, you may go.’ He then called all the demi-gods and told them, ‘you all go and take birth in Bhuloka as Yadavas.’
Yadu was the firstborn child of Yayati. And from Yadu originated the Yadava dynasty. A prominent person among Yadavas was Ahuka, who was wedded to the values of truth and righteousness. Ahuka had two sons, Devaka and Ugrasena. Devaka had one daughter by name, Devaki and Ugrasena had a son,Kamsa. Kamsa, however, had no sisters of his own. He therefore, treated his cousin sister, Devaki as his own with great love and affection. Shurasena was one among the Yadavas and he had a son named Vasudeva, who was a feudal prince. Vasudeva was truthful and a man of principles. King Ugrasena and his son Kamsa decided to give Devaki in marrriage to Vasudeva. However, Vasudeva was already married to another lady,Rohini. But the couple were childless. (Beacons of Divine Wisdom Part 2, p. 5)