Prior to being in the Celestis' service, he was known as the Great Nobodaddy, a posthuman assassin who worked for a time at the Remonstration Bureau. He claimed to be descended from old Earth gypsies.
After being turned into an Investigator, his battleform was covered in gypsy markings. He was best used at the siege of Poenari, fighting against the Turkish invaders and allowing Vlad III to escape. Ironically, Thirty-One was likely the one who killed Vlad over five hundred years later. (PROSE: The Book of the War)