Source:- Bhagavat Puran
There was a king named Gadhi (pronounced gaadhi). He had a daughter named Satyavati. A sage named Richik wanted to marry Satyavati. But the king did not find Richik as proper husband for Satyavati.
King Gadhi did not want to directly say no. He thought of a plan so that Richik himself felt that he was not a worthy suitor for Satyavati. Gadhi came up with an idea. He decided to put a difficult condition. He asked Richik to bring one thousand horses, each shining as moon, and each having one black ear. Richik had to fulfill this condition in order to marry Satyavati. Gadhi was under impression that Richik would not be able to fulfill the condition. After all he was so poor; how could he bring so many horses?
The sage Richik met god Varuna. Varuna gave Richik one thousand horses of the kind that king Gadhi had asked for. Richik gave the horses to Gadhi. Now Gadhi had no choice. He married Satyavati to Richik.
Once it so happened that Richak's wife satyavati and Satyavati's mother were both to give brith to a child. They requested the sage Richik to prepare an auspicious food so that the children would be good. Richik prepared one food for his wife Satyavati with Brahmana mantra (so that the child could be a brahmana). He prepared another food for his mother in law with kshatriya mantra (so that the child could be a kshatriya, i.e. a warrior). After that Richik went to take bath.
Meanwhile Satyavati's mother started thinking, "My daughter Satyavati is sage Richik's wife. This means that he must have prepared better food for Satyavati. One who ate that food will get a better child."
Thinking thus, Satyavati's mother requested Satyavati to exchange food with her. Satyavat was fine with any of the two foods and she did as her mother said.
Richik came to know about this. By this time the two ladies had already eaten the foods. He said to his wife Satyavat, "You have done a great wrong. I wanted your son to be a brahmana. But now, he will be a fierce kshatriya, able to punish everyone. Your brother, whom your mother will give birth, will be a learned scholar in spiritual science."
Satyavati wanted her son to be a scholar and not a warrior. He pladed with Richik that let her son be a scholar. Richik agreed and said, "Fne, your son will be a scholar in spiritual science. But your grandson will be a warrior."
Satyavati's mother gave birth to Visvamitra. Satyavati gave birth to Jaamadagni.
When Jamadagni grew up, he married Renuka. Their youngest son was named Ram. When he grew up, he was more commonly known as Parasuram because he kept Parasu weapon with him (a weapon in the form of an axe).
One day king Kartviryarjun visited the ashram of Jamadagni. Kartviryarjun had thousand hands and he was very powerful king. He easily defeated his enemies. He roamed over the Earth without opposition.
The sage Jamadagni received the King very well, along with the King's soldiers, ministers and carriers. He provided very tasty meal to his guests.
Kartviryarjun found this surprising. He wondered as to how a poor sage could arrange for so much food in such a short time. He asked Jamadagni the reason for it. Jamadagni told him that it was because of a divine cow that he had. The cow supplied all the food.
Kartviryarjun wanted to possess the cow and asked Jamadagni for it. Jamadagni needed the cow because it provided him with things needed for worship. Therefore, he refused to part with the cow. On the order from Kartaviryarjuna, his soldiers forcibly took away the cow to Mahishmati, Kartaviryarjuna's capital.
At that time Parsuram was not at home. When he came back, then he came to know the incident. Parasuram was very angry. Taking up his weapons, he went to Mahismati. He had got the knowledge of weapons from Lord Siva. He was dressed like a sage but he was holding weapons like a warrior.
Kartviryarjun sent a huge army to fight Parasuram. But Parasuram alone killed the entire army. Now, Kartviryarjun himself came in the battlefield. With his thousand arms, he could shoot arrows from five hundred bows at a time. But Parasuram raised enough arrows from his single bow to cut to pieces all the arrows and the bows of Kartviryarjun. Kartviryarjun uprooted huge trees and huge rocks from hills. He rushed towards Parasuram. Parasuram cut off all the arms of Kartviryarjun with his axe. After that he cut off Kartviryarjun's head.
Having killed Kartviryarjun, Parasuram released the cow and took it to his father's ashram. When Jamadagni heard the entire story, he felt that Parasuram should not have killed the king and should have forgiven him. He also felt that the society needed a powerful king like Kartviryarjun. Jamadagni also thought that, being a sage, Parasuram should do the job of worshipping God and providing knowledge to others. He said all this to Parasuram. He also asked Parasuram to visit holy places. As ordered by his father, Parasuram went on pilgrimage. His brothers also went with him.
One day Jamadagni was performing worship. He was meditating upon God. The sons of Kartviryarjun came and killed him. Jamadagni's wife Renuka cried loudly and took the name of her son Parasuram again and again. Parasuram and his brothers came to the ashram. They saw their father already killed.
Parasuram asked his brothers to take care of his father's dead body. He took up his weapons and went to Mahismati. There he killed the sons of Kartviryarjun. It looked as if there was a river of blood.
Parasuram killed many more of warrior class, who were using their power for wrongful deeds. He got the Earth rid of such people twenty one times.