King Mitrasaha belonged to the Ikshvaku Dynasty that ruled
Ayodhya. The story of the curse on Mitrasaha by Sage Vasishta is found in the
Uttara Ramayana. During a hunting expedition, Mitrausaha came across two tiger
cubs. The cubs were really two demons in disguise.
The king, who was unaware of it, killed one of the cubs with
an arrow. The other cub suddenly assumed his true form and warned Mitrasaha
that he would take revenge at the appropriate time.
The demon vanished and the king then returned to this
kingdom.
In due course of time, the king decided to perform
Ashwamedha Yajna and invited Sage Vasishta for this purpose.
The demon now appeared in the form of Sage Vasishta and told
the king that he had a desire to eat cooked meat. He asked the king to bring it
to his ashram secretly.
The king and his queen prepared meat and took it to the
Ashram of Sage Vasishta.
Sage Vasishta was furious to find meat in his ashram and
cursed the King to become a man-eating demon.
King Mitrasha protested that he knew nothing of the matter
and he just did what the sage had asked.
Sage Vasishta learnt through his inner eye of knowledge that
King Mitrasaha was not to blame.
However, the curse could not be taken back. It was reduced
to 12 years. The king then roamed the forest as a man-eating demon for 12
years.
It must be noted that there are several versions of the same
story in different Hindu scriptures.