(The SH in this name is pronounced like one between 's' in 'sip' and 'sh' in 'ship'. The TH is pronounced like 'th' in 'with'.)
Vishvaamithra was king-turned-sage . He lived through many ages from the ancient king Harischandra to Mahaabhaaratham times.
Vishvaamithra was a kshathriya, son of Gaadhi,son of Kushanaabha, son of Kusha,son of a Prajaapathi who came from Brahma himself.
Earlier, Vishvaamithra was ruling his kingdom. He had a hundred sons. He went around the countries once with his army, when he reached sage Vasishtha's hermitage in a forest. The sage arranged for them a wonderful feast with royal foods with the power of his cow Shabala which could give whatever is desired from her( kaamadhenu- kama=desire, dhenu=cow). The king wondered at athe power of the cow and asked the sage to give it to him for the benefit of his kingdom. But the sage refused unwilling to insult the cow's powers. Vishvaamithra was angry and took the cow by force. Then the cow requested the sage for help and with his permission, created varieties of army from her lowing ang her various body parts which instatntly destroyed the king's forces despite his stiff resistence against them. Visvhaamithra's hundred sons ran upon the sage to kill him but were burnt down by his shout itself. Vishvaamithra, losing his armies and sons, returned home and thought about revenge. He entrusted his kingdom to ane of the remaining sons at home and went to Himaalaya for undertaking penance upon Lord Shiva. When the God appeared and asked what his wish was, Vishvaamithra prayed to him for supernatural mastery over the archery and knowledge and command over all the asthras that were known to humans,rishis,demons and gods. Granted that, he haste returned and went to Vasishtha's hermitage to kill him. He threw the asthra Aagneya first. Vasishtha stopped it withhis shaft which swallowed the great asthra. Vishvaamithra was puzzled but employed , one after another, all the asthras he obtained by Shiva's grace. Vaaruna,Roudra, Ayndra, Paashupatha, Aysheeka,Maanava, Mohana, Santhaapana, Vilaapana,Soshana,Daarana,Vajra,Brahmapaasha,Kaalapaasha, Vaarunapaasha,Pynaaka, dry Ashani, wet ashani, danda, pyshaacha, krouncha, dharma's discus, kaala's discus,vaayavya, mathana,hayashiras, shakthi (kankaala), shakthi (musala), Vydyaadhara, mahaasthra, kaalasthra, thrishoola,kaapaala, kankana and many more. But all were swallowed by the sage's shaft . Finaly, Vishvaamithra used brahma asthra which too the sage swallowed down with his shaft. With that act, Vasishtha's body emanated fire balls all around and all the sages prayed to him to cool down. Vishvaamithra derided his asthras and their power and decided to go on penance to achived the same powers as Vasishtha did.
Burnt with anger and insult, Vishvaamithra went towards South and sunk in penance for a thousand years. Then brahma awarded him the status of raajarshi or king-sage ( king-turned-sage). He was not satisfied with that result ( Vasishtha was a brahmarhi or braahmana-turned-sage) and vontinued his penance. But he involved in the affair of a king Thrishanku who wanted to go to the heaven with mortal body and requested sage Vasishtha to prescribe a sacrifice for him for that purpose, which hs denied as it was impossible. Vishvaamithra was to spend all his accumulated powers for the king. In that futile task,he went so far as to create another universe for Thrishanku but was persuaded by sages and gods to drop the work in the middle.
Then Vishvaamithra went towards West and continued the penence at a place called Pushkara. But, after some years, he again involved with the affair of a boy Shunashshepha, who was bought by king Ambareesha of Ayodhya, from his parents for a price of one lakh cows, to be used as a sacrificial animal in the king's sacrifice. After releasing from from the danger, he continued his penance for another thousand years. Brahma appeared again and awarded him the status of sage ( rishi). Not satisfied with the elevatin from raajarshi to rishi, Visgvaamithra coninued his severe penance. But, after some years, he fell for a divine damsel Menaka and lived with her for ten years. Then he realised his eror and left Menaka to continue his penance.
This time, he went towards north. After a thousand years , Brahma again appeared before him and confered on him the status of maharsi (maha=great, sage=saint). Vishvaamithra was still dissatisfied that he was not acknowledged as master of senses and as free from passions . He went on penance for another thousand years. Then Indra sent a damsel Rambha to divert him from the path of penance. Vishvaamithra was angry with her for her mean efforts and cursed her to be lie as a stone for ten thousand years. He was sad that he could not maater anger. He decided to observe penance for another thousand years.
This time he went towards east and carried on his penance very severely. After another thousand years, all the sages prayed to Brahma to award Vishvaamithra what he wanted to get. And Brahma awrded him brahmarhi status. But Vishvaamithra insisted that sage Vasishtha himself should confirm his brahmarshi status. As Vasishtha did so, Vishvaamithra was happy. Such was his greatness.
Vishvaamithra was an example for revolution, rebellion and perseverance. Vengeance and wisdom were equally present in him. Unswerving perseverence in him is what is ideal to us.