

During the dynastic wars of the 1370s, between Portugal and Castile, Portuguese and Castilian privateers made for the Canaries for shelter or slaving raids. The raids and attacks of the Reconquista created captives on both sides, who were either ransomed or sold as slaves. Preparations were delayed and no expedition was mounted before Cerda's death in 1348. The Portuguese king Afonso IV immediately lodged a protest, as did Alfonso XI of Castile. Clement also urged the kings of Portugal and Castile to provide assistance to Cerda's expedition. In November 1344, Clement VI issued the bull Tu devonitis sinceritas bestowing upon Luis de la Cerda the title of sovereign "Prince of Fortuna". In 1344, the Castilian-French noble Luis de la Cerda (Count of Clermont and Admiral of France), and French ambassador to the papal court in Avignon, proposed to Pope Clement VI, conquering the islands and converting the native Guanches to Christianity. This expedition became the basis of Portuguese claims to the islands. The expedition spent five months mapping the islands. In 1341, a three-ship expedition sponsored by King Afonso IV of Portugal, set out from Lisbon for the Canary Islands. La Virgen de Candelaria, Patron of the Canary Islands After decolonization, this process increased in pace as church structures altered to reflect new political-administrative realities. These developing churches eventually graduated to regular diocesan status with the appointment of a local bishop. The process began with the formation of special jurisdictions, known as apostolic prefectures and apostolic vicariates.

Over time it was intended that a normal church structure would be established in the mission areas. In the early years, most mission work was undertaken by the religious orders. Important contemporary ecclesiastical documents taking a strong stance on enslaving or despoiling the indigenous peoples of the Americas was the ecclesiastical letter Pastorale officium and the superseding encyclical Sublimis Deus. Theologians such as Francisco de Vitoria and Bartolomé de las Casas drew up theological and philosophical bases for the defense of the human rights of the colonized native populations, thus creating the basis of international law, regulating the relationships between nations. Īntonio de Montesinos, a Dominican friar on the island of Hispaniola, was the first member of the clergy to publicly denounce all forms of enslavement and oppression of the indigenous peoples of the Americas. In Mexico, the early systematic evangelization by mendicants came to be known as the "Spiritual Conquest of Mexico". In the Americas and other colonies in Asia, and Africa, most missions were run by religious orders such as the Franciscans, Dominicans, Augustinians, and Jesuits.

Christian missions to the indigenous peoples ran hand-in-hand with the colonial efforts of Catholic nations. The evangelical effort was a major part of, and a justification for, the military conquests of European powers such as Portugal, Spain, and France. The Catholic Church during the Age of Discovery inaugurated a major effort to spread Christianity in the New World and to convert the indigenous peoples of the Americas and other indigenous peoples. The convent of San Augustin, a mission centre established at Yuriria, Mexico in 1550
