Eastern Catholicism

The Eastern Catholic Churches, also called the Oriental Catholic Churches and historically known as the Eastern-rite Catholic Churches or Uniate Churches, are 23 Eastern Christian particular churches sui iuris in full communion with the Pope in Rome. With about 18 million members, they make up a small part (about 1.5 percent) of the Catholic Church together with the Latin Church (Western 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 16 million, according to the Annuario Pontificio, thus making up a small part of the Catholic Church, with rest of its more than 1.2 billion members belonging to the Latin Church.

While the Maronite Church is considered the sole of them to permanently have remained in full communion with the Holy See, most of the other churches unified at some point from the 16th century onwards. The most recent of the Eastern Catholic Churches is the Eritrean Catholic Church, which was unified in 2015.

Full communion constitutes mutual sacramental sharing between the Eastern Catholic Churches and the Latin Church, including Eucharistic intercommunion. On the other hand, the liturgical traditions of the 23 Eastern Catholic churches, including Byzantine, Alexandrian, Armenian, East Syrian, and West Syrian, are shared with other Eastern Christian churches: the Eastern Orthodox, Oriental Orthodox, and Church of the East. Although some theological issues divide the Eastern Catholic churches from other Eastern Christian churches, they do admit members of the latter to the Eucharist and the other sacraments, as governed by Oriental canon law.

...
Wikipedia