Pope John XXI (Latin: Ioannes XXI; c. 1215 – 20 May 1277), born Pedro Julião (Latin: Petrus Iulianus), was head of the Catholic Church and ruler of the Papal States from 8 September 1276 to his death. Apart from Damasus I (from Roman Lusitania), he has been the only Portuguese pope. He is sometimes identified with the logician and herbalist Peter of Spain (Latin: Petrus Hispanus; Portuguese: Pedro Hispano), which would make him the only pope to have been a physician.