Catholicisation
conversion into Catholicism, and the expanding Catholic influence

Catholicisation (American English: Catholicization) refers mainly to the conversion of adherents of other religions to Catholicism, and the system of expanding Catholic influence in politics. Catholicisation was a policy of the Holy See through the Papal States, the Holy Roman Empire and the Habsburg monarchy. Sometimes this process is referred to as re-Catholicisation, although in many cases Catholicised people had never been Catholics before.
The term is also used for the communion of Eastern Christian churches into the Catholic Church; the Eastern Catholic Churches that follow the Byzantine, Alexandrian, Armenian, East Syrian and West Syrian Rites, as opposed to the Latin Church.
Catholic doctrine
The Congregation for the Evangelization of Peoples (Latin: Congregatio pro Gentium Evangelizatione), formerly Sacred Congregation for the Propagation of the Faith (Latin: Sacra Congregatio de Propaganda Fide) is the congregation of the Roman Curia responsible for missionary work and related activities.
In 1439 in Florence, the Declaration of Union was adopted, according to which "the Roman Church firmly believes that nobody, who does not belong to the Catholic Church, not only unbelievers, but Judeans (Jews), nor heretics, nor schismatics, cannot enter the kingdom of heaven, but all will go to the eternal fire, which is saved for devils and their angels, if they not before death turn to that church". The Council of Trent (1545–63) had the mission to gain, apart from "stray" Protestants, also the numerous schismatics from the Catholic Church in southeastern Europe.
Catholicisation and Uniatism
Polish–Lithuanian Commonwealth
During the period from the 16th to the 18th century, in eastern regions of Polish–Lithuanian Commonwealth and Kingdom of Hungary several successive campaigns of Catholicisation were undertaken in order to convert local Eastern Orthodox Christians into Catholicism.
Serbs
The Council of Trent had the mission to gain both Protestants, and Orthodox Christians in southeastern Europe. The Serbian Orthodox Church became targeted, the strongest pressure during the term of Pope Clement VIII (1592–1605), who used the difficult position of the Orthodox in the Ottoman Empire and conditioned the Serbian Patriarch to Uniatize in return for support against the Turks.
The public source identifies “Catholicisation” as conversion into Catholicism, and the expanding Catholic influence. This brief keeps that definition visible, then builds a research path around Catholicisation, conversion and Catholicism.
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A short description can identify a subject without explaining its stakes. For “Catholicisation”, the useful work is to connect “conversion into Catholicism, and the expanding Catholic influence” to the records capable of establishing context and consequence.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 17, 2026. The linked authority identifier is Q22907112. The first chronological checks are 1439, 1545, 1592 and 1605.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Catholicisation” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.