Mrikandu rishi was an ancient rishi, and he was an ardent devotee of Lord Shiva. He and his consort Marudmati worshipped Shiva for getting a noble son. As a result they had given the choice of either a pious son with a short life on earth or a child of unsound mind but with a long life.
Mrikandu rishi begged Shiva for giving him a noble son with a short life itself, and due to that the great Markandeya was born to them, and he had stolen the hearts of his parents through his childhood plays.
Markandeya had become a great devotee of Lord Shiva, and after he came to know, that he would die at the age of 16, he started worshipping Shiva in the form of Shivalingam. The messengers of Yama could not take away his life because of his continuous worship of Shiva. Yama then came personally and tried to take the life of Markandeya. But Markandeya tightly hugged the Shivalinga and began to chant the “NAMASHIVAYA” mantra. Lord Yama threw the noose on him, but accidentally the noose was fell around the Shivalingam, and from that, Lord Shiva had emerged and killed Yama for his wrong act. Therefore after the request of the divine gods, Shiva restored the life of Yama, and then gave the boon to Markandeya that he would live forever in this world.
After getting relieved from the fear of death, Markandeya sincerely worshipped Lord Shiva, and returned to his home, and was warmly welcomed by his parents, and they felt great happiness on seeing him again. After living with their lovely son for many years, Rishi Mrikandu and his consort Mata Marudmati went to the Himalayas and performed severe penance on Lord Shiva and attained SALVATION.
It is believed that even now the great Rishi Markandeya appears in the form of a 16 year old boy, and lives in the Rishi Mandala by meditating on Lord Shiva.