Pope John XXI

Pope John XXI (Latin: Ioannes XXI; c. 1215 – 20 May 1277), born Peter Juliani (Latin: Petrus Iulianus; Portuguese: Pedro Julião), was Pope from 8 September 1276 to his death in 1277. Apart from Damasus I (from Roman Lusitania), he has been the only Portuguese pope. He is usually 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.

"Pope John XXI" was actually the 20th pope named John, but decided to skip the number XX.

Life

Early life

Pedro Julião was probably born in Lisbon between 1210 and 1220. He started his studies at the episcopal school of Lisbon Cathedral and later joined the University of Paris, although some historians claim that he was educated at Montpellier. Wherever he studied, he concentrated on medicine, theology, logic, physics, metaphysics, and Aristotle's dialectic. He is traditionally and usually identified with the medical author Peter of Spain, an important figure in the development of logic and pharmacology. Peter of Spain taught at the University of Siena in the 1240s and his Summulae Logicales was used as a university textbook on Aristotelian logic for the next three centuries. At the court in Lisbon, he was the councilor and spokesman for King Afonso III in church matters. Later, he became prior of Guimarães.