The Pandavas were sent by their cousins, the Kauravas, into the exile. They were to pass twelve years in the forest and the thirteenth year in the disguise. If found out, they were to go to the forest for another period of twelve years. When the twelve years of exile were over, the Pandavas spent the thirteenth year in Viratnagar, the capital of Virat, the king of the Matsyas. They disguised themselves so that no one should recognize them.
The sacred sermons by Lord Krishna