Missionary work of the Catholic Church has often been undertaken outside the geographically defined parishes and dioceses by religious orders who have people and material resources to spare, and some of which specialized in missions. Eventually, parishes and dioceses would be organized worldwide, often after an intermediate phase as an apostolic prefecture or apostolic vicariate. Catholic mission has predominantly been carried out by the Latin Church in practice.
In the Roman Curia, missionary work is organised by the Congregation for the Evangelization of Peoples.
The New Testament missionary outreach of the Christian church from the time of St Paul was extensive throughout the Roman Empire.
During the Middle Ages, Christian monasteries and missionaries (such as Saint Patrick and Adalbert of Prague) fostered formal education and learning of religion, beyond the boundaries of the old Roman Empire. In the seventh century, Gregory the Great sent missionaries, including Augustine of Canterbury, into England. The Hiberno-Scottish mission began in 563 CE.
In the late thirteenth and early fourteenth centuries, Franciscans (such as William of Rubruck, John of Montecorvino, and Giovanni ed' Magnolia) were sent as missionaries to the Near and Far East. Their travels took them as far as China, in an attempt to convert the advancing Mongols to Christianity, especially the Great Khans of the Mongol Empire. (See also Catholic Church in China.)
Catholic Church and the Age of Discovery and Protectorate of missions
During the Age of Discovery, the Roman Catholic Church established a number of missions in the Americas and other colonies through the Augustinians, Franciscans, and Dominicans in order to spread Catholicism in the New World and to convert the indigenous peoples of the Americas and other indigenous people. At the same time, missionaries such as Francis Xavier as well as other Jesuits, Augustinians, Franciscans, and Dominicans were moving into Asia and the Far East. The Portuguese sent missions into Africa.