King Kaartaveerya-arjuna and his army visited Jamadagni, who fed his guest and the whole army with his divine cow; the king demanded the cow and Jamadagni refused because he needed the cow for his religious ceremonies. King Kaartaveerya-arjuna sent his soldiers to take the cow and Parashurama killed the entire army and the king with his axe (given to him by Shiva). In return, the princes beheaded Jamadagni. In revenge, Parashurama killed the entire clan of Kaartaveerya-arjuna, thus conquering the entire earth, which he gave to Kasyapa.
The women changed the messes, and so Jamadagni, the son of Richika, was born as a warrior-Brahman, and Vishvamitra, son of the Kshatriya Gadhi, was born as a priest.
The Mahabharata relates that Jamadagni engaged deeply in study and “obtained entire possession of the Vedas.” He went to King Renu or Prasenajit of the Solar race and demanded of him his daughter Renuka.
The sons of Kartavirya went in revenge to the hermitage of Jamadagni, and in the absence of Parasurama slew the pious sage without pity.
Jamadagni, according to Hindu mythology, was one of the great sages, a descendant of the sage Bhrigu.
Jamadagni, pleased, offered to grant a boon to Parashurama, who at once asked that his mother and brothers be restored to life and accepted into the family again.
Jamadagni was later killed by a Kshatriya king Kartavirya Arjuna, over a dispute over a divine calf.