Diophantus' place of birth within Arabia is unknown. It may have been Petra, also the birthplace of the 5th-century iatrosophist Gessius of Petra and a place associated in some manner with Diophantus' contemporary and fellow sophist, Epiphanius of Syria. He is not listed among the rhetors and sophists of Gerasa by Stephanus of Byzantium.[4][5]