Theodore Illion or Theodor Illion (born 1898 in Canada?) was a writer of travel books who claimed to have visited Tibet in the 1930s and discovered an underground city there. He published his Tibetan adventures under that name but later resorted to the pseudonyms Theodore Burang or Theodor Burang and more rarely Theodor Nolling to write various books and articles on Tibetan medicine. According to Professor Herbert Novak, a longtime friend of Theodore Illion, the latter was born in Canada in a wealthy family descended from a branch of the British royalty, the Plantagenets. He is supposed to have left home at a very young age.