Petrus Gillius (actually Pierre Gilles) (Albi, 1490 – Rome, 1555) was a French natural scientist, topographer and translator. He travelled and studied the Mediterranean and Orient, producing such works as De Topographia Constantinopoleos et de illius antiquitatibus libri IV,Cosmæ Indopleutes and De Bosphoro Thracio libri III, and a book about the fishes of the Mediterranean Sea. Among others, he spent several years in Istanbul, where he had been sent by the French King Francis I in order to find ancient manuscripts. Most of his books were published after his death by his nephew. He also translated Claudius Aelianus in 1533. He died in Rome of malaria, while he was following his patron, Cardinal Georges d'Armagnac.
