Pope Callixtus III , né Alfons de Borja, was Pope

Pope

The Pope is the Bishop of Rome, a position that makes him the leader of the worldwide Catholic Church . In the Catholic Church, the Pope is regarded as the successor of Saint Peter, the Apostle...

 from April 8, 1455 to his death in 1458.
Alfonso de Borja was born in La Torreta, now a neighbourhood of Canals, Valencia

Canals, Valencia

Canals is a municipality in the comarca of Costera in the Valencian Community, Spain.Limits with l'Alcúdia de Crespins, Cerdà, la Granja de la Costera, Xàtiva, Llanera de Ranes, Montesa, Torrella and Vallés and with Aielo de Malferit and l'Olleria .- Geography :Situated in Montesa's valley, between...

 -- today in Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 -- but at that time in the Kingdom of Valencia

Kingdom of Valencia

The Kingdom of Valencia , located in the eastern shore of the Iberian Peninsula, was one of the component realms of the Crown of Aragon. When the Crown of Aragon merged by dynastic union with the Crown of Castile to form the Kingdom of Spain, the Kingdom of Valencia became a component realm of the...

 under the Crown of Aragon

Crown of Aragon

The Crown of Aragon Corona d'Aragón Corona d'Aragó Corona Aragonum controlling a large portion of the present-day eastern Spain and southeastern France, as well as some of the major islands and mainland possessions stretching across the Mediterranean as far as Greece...

. His early career was spent as a professor of law

Law

Law is a system of rules and guidelines which are enforced through social institutions to govern behavior, wherever possible. It shapes politics, economics and society in numerous ways and serves as a social mediator of relations between people. Contract law regulates everything from buying a bus...

 at the University of Lleida

University of Lleida

The University of Lleida is a university based in Lleida , Spain. It was the first university in Catalonia and the whole Crown of Aragon...

 and then as a diplomat

Diplomat

A diplomat is a person appointed by a state to conduct diplomacy with another state or international organization. The main functions of diplomats revolve around the representation and protection of the interests and nationals of the sending state, as well as the promotion of information and...

 in the service of the Kings of Aragon

Aragon

Aragon is a modern autonomous community in Spain, coextensive with the medieval Kingdom of Aragon. Located in northeastern Spain, the Aragonese autonomous community comprises three provinces : Huesca, Zaragoza, and Teruel. Its capital is Zaragoza...

, especially during the Council of Basel (1431–1439).