BIRTH: Parasurama was born as fifth son to sage jamadagni and renuka devi. He hails from bramha i.e. sage chyavana is great grand father, grand father is sage rucheeka. Sage rucheeka after completion of his studieswanted to marry a suitable bride and is in search of that. In those days we have two prime dynasties ruling bharata desa i.e. surya vamsa and chandra vamsa. In chandra vamsa there is a king named kusika and he had a son name gadhi. Gadhi had a daughter by name satyavathi very beautiful prince. Sage rucheeka approached king gadhi and asked his daughter to marry him. The king was taken back by the brahmin wish but does not want to deny. He put a condition to him to give him 1000 horses with one ear black and entire body in white. Sage rucheeka agreed and done penance to please varuna and obtained through him the 1000 horses and offered to king Gadhi and got married with satyavathi. The princess satyavati also adjusted herself to the brahminic customs and living peacefully with sage rucheeka. After sometime she got worried that for herself as well as for her mother there is not male issues to continue the vamsa. She requested the sage rucheeka and he prayed to brahma and obtained two pots of rice pudding and offered it to both satyavathi and her mother clearly instructing that satyavahti will have child with brahminic qualities and her mother will have son with kshatriya qualities. He asked them to worship aswathha and raavi trees first and consume the rice pudding. Accordingly both prayed to the trees and consumed but the pots were interchaned knowingly or unknowingly. Both were conceived and sage rucheeka observed that the foetus of satyavathi is with kshatriya qualities and questioned her. Both were pleaded guilty and requested the sage how to overcome. The sage with his powers made the foetus of satyavathi to born with brahmanic qualities and his son with kshatriya qualities. Thus the son born to satyavathi is sage jamadagni with brahminic qualities and his son parasurama with kshatriya qualities.
The son born to sathyavathi mother with brahminic qualities is called as kusanaabha and in later days he was known to this yuga as sage viswamitra.