Editing Pope John XXI (section)

==Early life==
Pedro Julião was born in [[Lisbon]] between 1210 and 1220 to Julião Pais, chancellor of [[Afonso I of Portugal|Afonso Henriques]] and [[Sancho I of Portugal|Sancho I]],{{sfn|Branco|2001|p=524}} and his wife Mor Mendes. 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 ''{{lang|la|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 [[Afonso III of Portugal|King Afonso III]] in church matters. Later, he became [[Prior (ecclesiastical)|prior]] of Guimarães.

He was Archdeacon of Vermoim (Vermuy) in the Archdiocese of Braga.<ref>Conradus Eubel, ''Hierarchia catholica medii aevi'' Tomus I, editio altera (Monasterii 1913), p. 144.</ref> He tried to become [[Patriarch of Lisbon|bishop of Lisbon]] but was defeated. Instead, he became the Master of the school of Lisbon. Peter became the physician of [[Pope Gregory X]] (1271&ndash;1276) early in his reign. In March 1273, he was elected Archbishop of [[Braga]], but did not assume that post; instead, on 3 June 1273, [[Pope Gregory X]] created him [[Cardinal-Bishop of Frascati|Cardinal Bishop of Tusculum (Frascati)]].<ref>Conradus Eubel, ''Hierarchia catholica medii aevi'' Tomus I, editio altera (Monasterii 1913), p. 9.</ref>