Cornelia Horn examines and reconstructs the anti-Chalcedonian movement in Palestine on the basis of one of its most important witnesses, the fifth-century Life of Peter the Iberian by John Rufus. She uses textual as well as archaeological data to reconstruct the history of Peter the Iberian and his significant role in the early anti-Chalcedonian Church as well as the development of theological ideas and their connection with Palestinian asceticism.