Sura Sena was the chief of the Yadus and ruled over the town of Mathura. It is a sacred town. Once upon a time, at Mathura. Vasudeva drove in his chariot with his newly married wife Devaki. Kansa, the son of Ugrasena, held the reins of the horses himself, so eager was he to please his sister Devaki.
On the way, an incorporeal voice, addressing Kansa, said: “The eighth child of her whom you are now driving shall be your slayer.”
The cruel Kansa instantly took sword in hand and caught Devaki by her hair.
Vasudeva pacified him with by saying ” Why should you kill a female, your own sister, at marriage. Death is certain, this day or a hundred years hence. your younger sister, is motionless with fear. you have no fear from her. Surely I would make over to you her sons, from whom you have fear.”
Kansa desisted from his cruel act and Vasudeva went home with his bride, pleased for the time being.
In time Devaki brought forth eight sons and one daughter.
The truthful Vasudeva presented his first son Kirtimat to Kansa. The king admired the firmness of his brother-in-law and smilingly said:
“Take back this child. I have no fear from him. From your eighth born my death is ordained.” “So let it be” exclaimed Vasudeva, and he took back his son. But he had very little faith in the words of Kansa.
Kansa learned from Narada that Nanda, Vasudeva and others of their dan, their wives and even the clansmen of Kansa, his friends and relatives, were partial incarnations of the Devas. He further learned from the Rishi that preparations were being made for the lolling of the Daityas, whose power menaced the Earth.
When the Rishi left Kansa, he took all the members of the Yadu clan for Devas and every child of Devaki for Vishnu that was to kill him. He now confined Vasudeva and Devaki in his own house and put them in fetters. He put to death every son that was born to them. He knew himself to be Kalanemi who had been, in another birth, killed by Vishnu. He fell out with the Yadus, deposed his own father Ugra Sena and became himself the King.
With the alliance of the Magadhas (ancient Bihar) and other Asuras, Kansa tormented the Yadus. They fled away to other the kingdoms. Some only remained behind and they followed the behests of Kansa.