The Eastern Catholic Churches or Oriental Catholic Churches, also called the Eastern-rite Catholic Churches, and in some historical cases Uniate Churches,[a] are twenty-three Eastern Christianparticular churchessui iuris in full communion with the Pope in Rome, as part of the worldwide Catholic Church. Headed by patriarchs, metropolitans, and major archbishops, the Eastern Catholic Churches are governed in accordance with the Code of Canons of the Eastern Churches, although each church also has its own canons and laws on top of this, and the preservation of their own traditions is explicitly encouraged. The total membership of the various churches accounts for about 18 million, according to the Annuario Pontificio (the annual directory of the Catholic Church), thus making up about 1.5 percent of the Catholic Church, with the rest of its more than 1.2 billion members belonging to the Latin Church, also known as the Western Church or the Roman Catholic Church.
There are different meanings of the word rite. Apart from its reference to the liturgical patrimony of a particular church, the word has been and is still sometimes, even if rarely, officially used of the particular church itself. Thus the term Latin rite can refer either to the Latin Church or to one or more of the Western liturgical rites, which include the majority Roman Rite but also the Ambrosian Rite, the Mozarabic Rite, and others.
A group of Christian faithful linked in accordance with the law by a hierarchy and expressly or tacitly recognized by the supreme authority of the Church as autonomous is in this Code called an autonomous Church (canon 27).
A rite is the liturgical, theological, spiritual and disciplinary patrimony, culture and circumstances of history of a distinct people, by which its own manner of living the faith is manifested in each autonomous [sui iuris] Church.
The rites treated in CCEO, unless otherwise stated, are those that arise from the Alexandrian, Antiochene, Armenian, Chaldean and Constantinopolitan traditions" (canon 28) (not just a liturgical heritage, but also a theological, spiritual and disciplinary heritage characteristic of peoples' culture and the circumstances of their history).
When speaking of Eastern Catholic Churches, the Latin Church's 1983 Code of Canon Law (1983CIC) uses the terms "ritual Church" or "ritual Church sui iuris" (canons 111 and 112), and also speaks of "a subject of an Eastern rite" (canon 1015 §2), "Ordinaries of another rite" (canon 450 §1), "the faithful of a specific rite" (canon 476), etc. The Second Vatican Council spoke of Eastern Catholic Churches as "particular Churches or rites".(n. 2)
In 1999, the United States National Conference of Catholic Bishops stated: "We have been accustomed to speaking of the Latin (Roman or Western) Rite or the Eastern Rites to designate these different Churches. However, the Church's contemporary legislation as contained in the Code of Canon Law and the Code of Canons of the Eastern Churches makes it clear that we ought to speak, not of rites, but of Churches. Canon 112 of the Code of Canon Law uses the phrase 'autonomous ritual Churches' to designate the various Churches." And a writer in a periodical of January 2006 declared: "The Eastern Churches are still mistakenly called 'Eastern-rite' Churches, a reference to their various liturgical histories. They are most properly called Eastern Churches, or Eastern Catholic Churches." However, the term "rite" continues to be used. The 1983CIC forbids a Latin bishop to ordain, without permission of the Holy See, a subject of his who is "of an Eastern rite" (not "who uses an Eastern rite", the faculty for which is sometimes granted to Latin clergy).Pope Benedict XVI wrote, in his 2007 motu proprioSummorum Pontificum, that "any Catholic priest of the Latin rite",[f] under certain conditions, "may use either" edition of the Roman Missal.
The term "uniate" itself, once used with pride in the Roman communion, had long since come to be considered as pejorative. "Eastern Rite Catholic" also was no longer in vogue because it might suggest that the Catholics in question differed from Latins only in the externals of worship. The Second Vatican Council affirmed rather that Eastern Catholics constituted churches whose vocation was to provide a bridge to the separated churches of the East.