There is description in the Brahma Purana (Purva Bhag,Addhyaya 1, shloka 5,6,7) that in the beginning of the Kalpa, a very sacred mahayagya was performed for one thousand years. The organizer of this mahayagya was Brahmaji himself accompanied by His wife Ila. The role of Shamitraka was performed by intelligent and radiant Mrityudev himself.
