1. Kamsa was the tyrant ruler of the Vrishni kingdom, with its capital at Mathura.

1. Kamsa was the tyrant ruler of the Vrishni kingdom, with its capital at Mathura.
Kamsa is variously described in Hindu literature as either a human or an asura; The Puranas describe him as an asura, while the Harivamsa describes him as an asura reborn in the body of a man.
Kamsa was the cousin of Devaki, the mother of the deity Krishna; Krishna ultimately fulfilled a prophecy by slaying Kamsa.
However, out of ambition, and upon the advice of his personal confidantes, Banasura and Narakasura, Kamsa decided to overthrow his father, and install himself as the King of Mathura.
Therefore, upon the guidance of another advisor, Chanura, Kamsa decided to marry Asti and Prapti, the daughters of Jarasandha, King of Magadha.
Kamsa was in his previous birth a demon called Kalanemi, who was slain by the god Vishnu.
Kamsa is generally described as the son of the Yadava ruler, Ugrasena.
However, some texts such as the Padma Purana state that Kamsa was not the biological son of Ugrasena.
Kamsa soon becomes pregnant with a son, whom she curses be killed by a member of his family.
In childhood, Kamsa was trained by the other Yadavas, who were famous warriors, along with his eight brothers.
Kamsa acquired Jarasandha's attention when the latter tried to invade Mathura.
Kamsa intended to kill his cousin Devaki, fearing the prophecy that her eighth child was fated to kill him.
Kamsa accepted this proposition and spared Devaki because she herself was not a threat to him.