Vishwamitra was born in the descent of Kaushik and was the son of Gaadhi. He was called Kaushik because of his lineage.

Once, while he was a king, Vishwamitra visited the hermitage of sage Vashishta along with his troops. Vashishta treated him very well with the help of Kamadhenu (a celestial cow which fulfills all the desires).

When Vishwamitra learnt about the wonderful Kamadhenu, he desired to acquire the cow. But Vashishta did not agree to part with the cow. Vishwamitra then tired to acquire it by force. Vashishta defeated him and his army with the creation of thousands of warriors.

The defeated Vishwamitra observed penance to acquire supernatural powers in order to defeat Vashishta. Pleased by his penance, Lord Shiva blessed him with a divine weapon. But Vashishta even annihilated that divine weapon in his Brahmadanda.

Ultimately, Vishwamitra decided to realize Brahma instead of fighting with Vashishta.

In the path of realization of the Lord, anger, lust, attachment, greed etc. act as barriers and impediment and ultimately lead to hell. No matter how much learned a person is, no matter how intelligent or great a hermit is, but all his knowledge, intelligence and powers render useless if he has human weakness.

So, while Vishwamitra was performing penance, Indra afraid by his penance sent the elf Menaka to disrupt his penance. She was successful in her attempt.

Once, Trishanku requested Vishwamitra to perform a Yagya so that he could go to the heaven with his physical body. Vishwamitra agreed to perform the Yagya. All the sages came to the Yagya except the sage Vashishta and his sons. Angered by this insult, Vishwamitra killed all his sons and sent Trishanku to the heaven with his physical body. But the deities did not allow him to enter heaven and pushed him back. But aware of his fall from the heaven, Vishwamitra fixed him in the sky.

Vishwamitra never became dejected even after so many failures during the course of his penance. He became so powerful that he began a second creation of the world. He created numerous living beings which were not even created by Brahma.

While he was in the process of creating a man and had already created the head, Brahma, apprehending that if the head has been created, he could create the rest of the body as well, stopped Vishwamitra from creating the second world and gifted him with the title of Brahmaharshi as a compensation. Since, the head portion had already been created, Vishwamitra asked him what should be done with it. Brahma named the head as Sriphala (coconut) and said that without this Sriphala no Yagya would be complete. Hence supreme sacrifice is made during every Yagya by offering Sriphala (coconut).

Ultimately, Vashishta too accepted him as Brahmaharshi after Vishwamitra had abandoned his weapons. While performing a Yagya, the followers of demon king Ravana, Marichi and Subahu desecrated the sight by placing pieces of flesh, filth etc. Because of this Vishwamitra was unable to complete his Yagya.

When he came to know that Shri Vishnu had taken incarnation as Rama to unburden the earth from the evils and sins, he went to Ayodhya and with the permission of the king Dashrath, he brought Rama and Lakshmana to his hermitage.

When Lord Rama killed Taraka by one shot of his arrow, Vishwamitra came to realize about His divinity and believed that He was indeed an incarnation of the Lord Vishnu and later he trained both Rama and Lakshmana and gave to them many divine weapons.

It was Vishwamitra who took both the brothers along with him to Janakpura to participate in Sita Swayamvara and he was the one on whose order Rama broke the bow and as a result of that got married to Sita.

After the completion of their education when both Rama and Lakshmana returned to Ayodhya, Vishwamitra too accompanied them. He was well received and was treated well by king Dashrath. When Shri Rama went into exile, king Janaka along with him met them at Chitrakoot.

The whole life of Vishwamitra was spent in observing penance and being benevolent towards the humanity. Shri Rama revered Vishwamitra just like His own teacher Vashishta.