The Second Vatican Council document, Orientalium Ecclesiarum, built on previous reforms to reaffirm the right of Eastern Catholics to maintain their distinct practices.

However, since the 19th century, diaspora has spread to Western Europe, the Americas and Oceania in part because of persecution, where eparchies have been established to serve adherents alongside those of Latin Church dioceses.

[citation needed] This distinction, by which the words oriental and eastern that in themselves have exactly the same meaning but are used as labels to describe two different realities, is impossible to translate in most other languages, and is not universally accepted even in English.

At the Council of Florence (1431–1445), these controversies about Western theological elaborations and usages were identified as, chiefly, the insertion of "Filioque" into the Nicene Creed, the use of unleavened bread for the Eucharist, purgatory, and the authority of the pope.

In spite of that event, for many years both churches continued to maintain friendly relations and seemed to be unaware of any formal or final rupture.

In 1190, Eastern Orthodox theologian Theodore Balsamon, who was patriarch of Antioch, wrote that "no Latin should be given Communion unless he first declares that he will abstain from the doctrines and customs that separate him from us".

In 1438, the Council of Florence convened, which featured a strong dialogue focused on understanding the theological differences between the East and West, with the hope of reuniting the Catholic and Orthodox churches.

[34] On 30 November 1894, Pope Leo XIII issued the apostolic constitution Orientalium dignitas, in which he stated: The Churches of the East are worthy of the glory and reverence that they hold throughout the whole of Christendom in virtue of those extremely ancient, singular memorials that they have bequeathed to us.

They swiftly gave forth their yield: there flowered in first blush the glories of preaching the True Faith to the nations, of martyrdom, and of holiness.

When blessed Peter, the Prince of the Apostles, intended to cast down the manifold wickedness of error and vice, in accord with the will of Heaven, he brought the light of divine Truth, the Gospel of peace, freedom in Christ to the metropolis of the Gentiles.

It declared that "it is the mind of the Catholic Church that each individual Church or Rite should retain its traditions whole and entire and likewise that it should adapt its way of life to the different needs of time and place" (n. 2), and that they should all "preserve their legitimate liturgical rite and their established way of life, and ... these may not be altered except to obtain for themselves an organic improvement" (n. 6; cf.

[16] It confirmed and approved the ancient discipline of the sacraments existing in the Eastern churches, and the ritual practices connected with their celebration and administration, and declared its ardent desire that this should be re-established if circumstances warranted (n. 12).

It expressed the wish that, where the permanent diaconate (ordination as deacons of men who are not intended afterwards to become priests) had fallen into disuse, it should be restored (n. 17).

In like manner the Episcopal bodies of today are in a position to render a manifold and fruitful assistance, so that this collegiate feeling may be put into practical application.

8 Likewise the commission acknowledged that "certain civil authorities [who] made attempts" to force Eastern Catholics to return to the Orthodox Church used "unacceptable means".[42]: n.

12  Thus the commission concluded that the "missionary apostolate, ... which has been called 'uniatism', can no longer be accepted either as a method to be followed or as a model of the unity our Churches are seeking."[42]: n.

Nonetheless, the ecclesial communities which emerged in these historical circumstances have the right to exist and to undertake all that is necessary to meet the spiritual needs of their faithful, while seeking to live in peace with their neighbours.

'[43] The 1996 Instruction for Applying the Liturgical Prescriptions of the Code of Canons of the Eastern Churches brought together, in one place, the developments that took place in previous texts,[44] and is "an expository expansion based upon the canons, with constant emphasis upon the preservation of Eastern liturgical traditions and a return to those usages whenever possible—certainly in preference to the usages of the Latin Church, however much some principles and norms of the conciliar constitution on the Roman rite, "in the very nature of things, affect other rites as well.

It seemed opportune, therefore, to gather them in a systematic whole, completing them with further clarification: thus, the intent of the Instruction, presented to the Eastern Churches which are in full communion with the Apostolic See, is to help them fully realize their own identity.

The authoritative general directive of this Instruction, formulated to be implemented in Eastern celebrations and liturgical life, articulates itself in propositions of a juridical-pastoral nature, constantly taking initiative from a theological perspective.[44]: n.

5 Past interventions by the Holy See, the Instruction said, were in some ways defective and needed revision, but often served also as a safeguard against aggressive initiatives.

[h] This attitude may have led to interventions in the Eastern liturgical texts which today, in light of theological studies and progress, have need of revision, in the sense of a return to ancestral traditions.

[45][i] The Catholic patriarchs and major archbishops derive their titles from the sees of Alexandria (Coptic), Antioch (Syriac, Melkite, Maronite), Baghdad (Chaldean), Cilicia (Armenian), Kyiv-Halych (Ukrainian), Ernakulam-Angamaly (Syro-Malabar), Trivandrum (Syro-Malankara), and Făgăraş-Alba Iulia (Romanian).

While they accept the canonical authority of the Holy See of Rome, they retain their distinctive liturgical rites, laws, customs and traditional devotions, and have their own theological emphases.

Terminology may vary: for instance, diocese and eparchy, vicar general and protosyncellus, confirmation and chrismation are respectively Western and Eastern terms for the same realities.

Members by right are the Patriarchs and the Major Archbishops of the Oriental Churches and the President of the Pontifical Council for the Promotion of Unity among Christians.

This celibacy mandate for Eastern Catholic priests in the United States was restated with special reference to Ruthenians by the 1 March 1929 decree Cum data fuerit, which was renewed for a further ten years in 1939.

Shio Batmanishviii [sic], and two Georgian Catholic priests of the Latin Church were executed by the Soviet authorities in 1937 after having been held in captivity in Solovki prison and the northern gulags from 1923.

[77] Vasyl Ovsiyenko [uk] mentions, on the Ukrainian Helsinki Human Rights Union website, that "the Catholic administrator for Georgia Shio Batmalashvili" was one of those executed as "anti-Soviet elements" in 1937.

Countries in which Christians have suffered acute discrimination, persecution and often death include: Somalia, Syria, Iraq, Afghanistan, Saudi Arabia, Maldives, Pakistan, Iran, Yemen, Palestinian Territories, Egypt, Turkey, Qatar, Uzbekistan, Jordan, Oman, Kuwait, Kazakhstan, Tajikistan, Turkmenistan, Kyrgyzstan, Eritrea, United Arab Emirates, and North Caucasus.