Eastern Catholic liturgy in the context of "Eastern Catholic Churches"

The Catholic Church (Latin: Ecclesia Catholica), also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institutions and has played a prominent role in the history and development of Western civilization. The Church consists of 24 sui iuris (autonomous) churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and eparchies around the world, each overseen by one or more bishops. The pope, who is the bishop of Rome, is the chief pastor of the church.

The core beliefs of Catholicism are found in the Nicene Creed. The Catholic Church teaches that it is the one, holy, catholic and apostolic church founded by Jesus Christ in his Great Commission, that its bishops are the successors of Christ's apostles, and that the pope is the successor of Saint Peter, upon whom primacy was conferred by Jesus Christ. It maintains that it practises the original Christian faith taught by the apostles, preserving the faith infallibly through scripture and sacred tradition as authentically interpreted through the magisterium or teaching office of the church. The Roman Rite and others of the Latin Church, the Eastern Catholic liturgies, and communities and societies such as mendicant orders, enclosed monastic orders, third orders and voluntary charitable lay associations reflect a variety of theological and spiritual emphases in the church.

Eastern Christianity comprises Christian traditions and church families that originally developed during classical and late antiquity in the Eastern Mediterranean region or locations further east, south or north. The term does not describe a single communion or religious denomination. Eastern Christianity is a category distinguished from Western Christianity, which is composed of those Christian traditions and churches that originally developed further west.

Major Eastern Christian bodies include the Eastern Orthodox Church and the Oriental Orthodox Churches, along with those groups descended from the historic Church of the East (also called the Assyrian Church), as well as the Eastern Catholic Churches (which are in communion with Rome while maintaining Eastern liturgies), and the Eastern Protestant churches. Most Eastern churches do not normally refer to themselves as "Eastern", with the exception of the Assyrian Church of the East and its offshoot, the Ancient Church of the East.

Latin liturgical rites, or Western liturgical rites, is a large family of liturgical rites and uses of public worship employed by the Latin Church, the largest particular church sui iuris of the Catholic Church, that originated in Europe where the Latin language once dominated and further by Western Rite Orthodoxy and Independent and Old Catholicism. Its language is now known as Ecclesiastical Latin. The most used rite is the Roman Rite.

The Latin rites were for many centuries no less numerous than the modern Eastern Catholic liturgical rites. The number of Latin rites and uses is now much reduced. In the aftermath of the Council of Trent, in 1568 and 1570 Pope Pius V suppressed the breviaries and missals that could not be shown to have an antiquity of at least two centuries in favor of the Roman Missal and Roman Breviary. Many local rites that remained legitimate even after this decree were abandoned voluntarily, especially in the 19th century, in favor of the Tridentine Mass and other Roman Rite rituals. In the second half of the 20th century, most of the religious orders that had a distinct liturgical rite chose to adopt in its place the Roman Rite as revised in accordance with the decrees of the Second Vatican Council (see Mass of Paul VI). A few such liturgical rites persist today for the celebration of Mass, since 1965–1970 in revised forms, but the distinct liturgical rites for celebrating the other sacraments have been almost completely abandoned.