Shishupala was killed by Sri Krishna during the Rajasuya
Yajna conducted by Yudhisthira at the Indraprastha. Shishupala was killed by
Sri Krishna to give moksha to him. Story of his birth is found in the Puranas
and Mahabharata.
Shishupala was Jaya, one of the guards of Vaikunta, Vishnu’s
abode. He along with Vijaya had once denied entry to Sanat Kumaras. The sages
cursed them to be born on earth.
Jaya and Vijaya then prayed to Vishnu for a solution to the
curse. Vishnu told them that they can take seven births on earth as his
ordinary devotees or take three births as his enemies.
Jaya and Vijaya opted for three births as enemies as they
wanted to return to Vaikunta at the earliest.
They pleaded that they should meet their end in each birth
at the hands of Vishnu.
Thus Jaya was born as Shishupala when Bhagvan Vishnu
appeared as Sri Krishna.
He was killed by Sri Krishna during the Rajasuya Yajna
conducted by Yudhisthira at the Indraprastha. Krishna
had promised Shishupala’s mother that he will forgive 100 insults of her son.
Shishupala’s insults crossed the 100 limit at the Rajasuya
Yajna and Sri Krishna killed him with his Sudarshana Chakra.
When Shishupala’s head was severed a glow of
light emerged from him and merged with Sri Krishna.