Byzantine Catholic vs Roman Catholic: One Church, Two Ways of Worship

Catholicism DemystifiedSee all 45 articles in this series

Byzantine Catholics share one faith and one pope with Roman Catholics, and they pray in a different rite. Their churches, in full communion with Rome, follow the rite of Constantinople. The differences are of form: the Divine Liturgy instead of the Mass, Communion for infants at baptism, married priests, and in places another calendar and Creed wording.

There are fourteen Byzantine Catholic churches, the largest of them the Ukrainian Greek Catholic Church, and they have their own code of church law. A Roman Catholic who goes to one of their Divine Liturgies finds icons on a screen across the sanctuary and Communion given with a spoon, and may receive Communion there and fulfil the Sunday obligation. The faith is the same, and the Church calls the two ways of praying it “of equal dignity.”

Our free tool, Compare Christian Denominations, sets any two of 23 churches side by side on 55 questions.

Topic	Byzantine Catholic	Roman Catholic
Rite	Byzantine, from the Church of Constantinople	Roman rite of the Latin Church
Main service	Divine Liturgy of St John Chrysostom or St Basil	The Mass of the Roman Missal
Communion bread	Leavened	Unleavened
Infants	Baptism, chrismation and Communion together	Baptism; Confirmation and First Communion years later
Priests	Married men may be ordained; bishops are celibate	Normally celibate
Calendar	Varies; the Ukrainian church left the Julian for fixed feasts in 2023	Gregorian
Creed	May be said without “and the Son”	Says “and the Son”
Pope	Full communion; in patriarchal and major archiepiscopal churches the synod elects the head, and Rome must recognize or confirm the election	Full communion
Church law	Code of Canons of the Eastern Churches, 1990	Code of Canon Law, 1983

It is one of the 23 Eastern churches that, with the Latin Church, make up the Catholic Church. Each is a church sui iuris, a self-governing church with its own rite, law and leadership. The Second Vatican Council taught that all of them, “whether of the East or the West,” are “entrusted to the pastoral government of the Roman Pontiff” and are “of equal dignity,” though they differ “in rite (to use the current phrase), that is, in liturgy, ecclesiastical discipline, and spiritual heritage” (Orientalium Ecclesiarum 3). Are there Catholic denominations? describes all 24.

The Byzantine churches are the ones that use the rite of Constantinople. Adrian Fortescue, writing in the Catholic Encyclopedia in 1908, called it, after the Roman rite, “by far the most widely spread in the world,” and noted that it is followed by all the Orthodox churches as well. Many Byzantine Catholic churches call themselves Greek Catholic, after the Greek origin of the rite, whatever language they pray in.

Fourteen of the 23 Eastern Catholic churches are Byzantine: the Ukrainian, Ruthenian, Slovak, Hungarian, Romanian, Melkite, Italo-Albanian, Belarusian, Russian, Bulgarian, Macedonian, Albanian and Greek churches, and the Eparchy of Križevci in Croatia and Serbia (an eparchy is an Eastern diocese).

The Ukrainian Greek Catholic Church is led by a major archbishop in Kyiv, a head elected by the church’s own synod, as a patriarch is, in an election Rome must recognize or confirm. Catholic World Report calls it the largest of all the Eastern Catholic churches, though by a narrow margin. In a chart the US bishops published from the figures in the Annuario Pontificio for 2018, it had about 4.4 million members, 25 percent of Eastern Catholics, against about 4.3 million, or 24 percent, for the Syro-Malabar Church of India. The Annuario’s counts run behind its date: the edition for 2026, for instance, reports the number of Catholics at the end of 2024.

The Melkite Greek Catholic Church, with about 1.5 million members in the same chart, takes its name from the Syriac word for king; the Melkites were, in Fortescue’s phrase of 1911, “the emperor’s party,” the Christians of Syria, Palestine and Egypt who held to the Council of Chalcedon in 451. It has a patriarch who holds the titles of Antioch, Alexandria and Jerusalem, and is present in Lebanon, Syria, Israel and Palestine, Brazil and Argentina.

It is the same sacrifice in a different form. The Byzantine churches celebrate the Divine Liturgy of St John Chrysostom, or on a few days a year that of St Basil, where the Latin Church celebrates the Mass of the Roman Missal. In Fortescue’s description of the rite, the sanctuary is screened off by the iconostasis, a screen across the church “covered with a great number of pictures of Christ and the saints,” and the priest gives Communion with a spoon, the consecrated bread dipped in the chalice, to people who stand to receive. The Catechism, for Byzantine and Roman Catholics alike, teaches that “the sacred image, the liturgical icon, principally represents Christ” (1159).

The bread is leavened in the Byzantine rite. The Latin rule is that the bread “must be unleavened” (General Instruction of the Roman Missal 320). The Council of Florence settled in 1439 that both are valid: “the body of Christ is truly confected in both unleavened and leavened wheat bread,” each priest following “the custom of his western or eastern church.”

The Creed is the same Nicene Creed, with one phrase that differs in some places. The Latin Creed says the Holy Spirit proceeds “from the Father and the Son”; the original Greek text says from the Father. The Vatican’s office for Christian unity wrote in 1995 that the Catholic Church “has refused the addition” of the words “and the Son” to the Greek text of the Creed “in the Churches, even of Latin rite, which use it in Greek,” and that “the liturgical use of this original text remains always legitimate in the Catholic Church.” The Council of Florence had taught that “and from the Son” “was licitly and reasonably added to the creed.” The Byzantine Catholic Archeparchy, or archdiocese, of Pittsburgh has published a text, written in 1981, that prints the words “(and the Son)” in brackets.

Christianity: What Christians Have Believed for 2,000 Years is a free course of eighteen short lessons on what Christians believe, from the life of Jesus to worship and the sacraments.

The language also varies with the church: Hungarian Greek Catholics pray in Hungarian, Bulgarian Byzantine Catholics in Bulgarian and Church Slavonic, the Eparchy of Križevci in Croatian and Church Slavonic among others.

Yes. The Catechism describes the Eastern practice: “In the Eastern rites the Christian initiation of infants also begins with Baptism followed immediately by Confirmation and the Eucharist, while in the Roman rite it is followed by years of catechesis before being completed later by Confirmation and the Eucharist” (1233). Confirmation is called chrismation in the East, and the Catechism lists the sacrament as “Confirmation or Chrismation” (1113). A Byzantine Catholic child has therefore received all three sacraments of initiation before learning to talk.

A married man can be ordained a priest; a priest cannot marry after ordination. The Catechism explains: “In the Eastern Churches a different discipline has been in force for many centuries: while bishops are chosen solely from among celibates, married men can be ordained as deacons and priests” (1580). In the Latin Church, priests are “normally chosen from among men of faith who live a celibate life” (1579). A Vatican decree of 2014 notes that every Eastern Catholic church may admit married men to the priesthood except the Syro-Malabar and Syro-Malankara churches, which are not Byzantine.

For more than a century, married Eastern Catholic priests were barred, with exceptions, from serving in lands outside their churches’ traditional territories. The bar began with the Ruthenians, Byzantine Catholics of the Carpathian Mountains. After thousands of them emigrated to the United States from the 1880s, Latin bishops objected to their married priests, and in 1890 Rome barred married Ruthenian clergy from living in the United States. Decrees of 1929 and 1930 extended the bar to married Eastern priests emigrating to North and South America, Canada and Australia. The first put it plainly: “Priests of the Greek-Ruthenian rite, who want to come and dwell in the United States of North America, must be celibate.” The 2014 decree records the cost: an estimated 200,000 Ruthenian faithful, left without priests of their own rite, joined the Orthodox. Even under the bar “exceptions were conceded,” with the Holy See’s authorization, and in 2008 Rome kept the rule while allowing a dispensation, reserved to the Holy See, in exceptional cases. In December 2013 Pope Francis approved the power to allow married Eastern priests to serve “also outside the traditional Eastern territory,” and the decree was published in 2014. Where Eastern Catholics abroad have their own bishops, those bishops now decide; where they have none and are in the care of Latin bishops, Rome still decides, in “concrete and exceptional cases.”

Yes, and receive Communion there. Canon 923 of the Code of Canon Law says: “The Christian faithful can participate in the eucharistic sacrifice and receive holy communion in any Catholic rite.” The Sunday obligation is met the same way, since canon 1248 counts anyone who “assists at a Mass celebrated anywhere in a Catholic rite.”

Going regularly does not make a Roman Catholic a Byzantine Catholic. Canon 112 says that “the practice, however prolonged, of receiving the sacraments according to the rite of another ritual Church sui iuris does not entail enrollment in that Church”; a formal change of church needs permission from Rome or one of the routes the canon lists, such as marriage.

Mostly by communion with Rome. The worship is the same rite, so a Byzantine Catholic liturgy and an Orthodox one look and sound alike. The Byzantine Catholic churches are in full communion with the pope; the Orthodox churches are not, and Orthodox Christians are not permitted by their own churches to receive Communion in Catholic ones. Catholic law does not forbid it: canon 844 §3 of the Code of Canon Law lets a Catholic priest give Communion to members of Eastern churches not in full communion with Rome “if they seek such on their own accord and are properly disposed.” Orthodox vs Catholic covers the wider differences between the two churches.

Most Byzantine Catholic churches began when Orthodox bishops, priests or communities entered communion with Rome; Catholic World Report says the Italo-Albanian church never lost that communion. The Ukrainian and Belarusian churches trace their origin to the Union of Brest: agreed with the pope on 23 December 1595 and proclaimed at Brest-Litovsk on 16 October 1596. The Ruthenian church dates from the Union of Uzhhorod, when on 24 April 1646, in Pope John Paul II’s words, “63 Byzantine-rite priests of the Eparchy of Mukacheve” were “received into full communion with the See of Peter.”

The two churches’ official dialogue has since looked back on these unions. In 1993 its joint commission, meeting at Balamand in Lebanon, said that such unions brought “the breaking of communion with their Mother Churches of the East” and became “a source of conflicts and of suffering in the first instance for the Orthodox but also for Catholics.” Certain Orthodox churches, the statement notes, had suspended their participation in the dialogue. The joint commission’s statement held that “uniatism” “can no longer be accepted either as a method to be followed nor as a model of the unity our Churches are seeking,” and that the Eastern Catholic churches “have the right to exist and to act in answer to the spiritual needs of their faithful.” Pope Francis and Patriarch Kirill of Moscow said the same in 2016, describing “uniatism” as “the union of one community to the other, separating it from its Church,” and adding that “Orthodox and Greek Catholics are in need of reconciliation and of mutually acceptable forms of co–existence.”

For most of the first millennium, yes: the empire’s church, the Church of Constantinople, was in full communion with Rome, and both confessed the “one, holy, catholic, and apostolic Church” of the Nicene Creed. Its liturgy, from the imperial capital Constantinople, the old Byzantium, is the Byzantine rite. John Paul II wrote that when the Rus’, the people of medieval Kyiv and its lands, were baptized in 988, “the Churches of the Byzantine tradition and the Church of Rome were still living in full communion.”

The break is usually dated to 1054, when the pope’s legate, Cardinal Humbert, excommunicated Patriarch Michael Cerularius and the patriarch’s synod excommunicated the legates. In 1965 Pope Paul VI and Ecumenical Patriarch Athenagoras I declared that “these censures were not intended to break ecclesiastical communion between the Sees of Rome and Constantinople,” and they committed the excommunications to oblivion. The division grew all the same. Reunions agreed at the Councils of Lyons in 1274 and Florence in 1439 did not last; the union of Florence was proclaimed in the church of Hagia Sophia in December 1452, months before Constantinople fell to the Turks in 1453.

The Church of Constantinople continues today as the Ecumenical Patriarchate, first among the Orthodox churches. The Byzantine Catholic churches worship in its rite while belonging to the Catholic Church. So, Sunday by Sunday, they say with Rome and with the churches of the first millennium the words that once held them all together: “one, holy, catholic, and apostolic Church.”

---

• Roman Catholic vs Catholic: the same Church, with exceptions
• Is Catholicism a denomination?
• Eastern Orthodox Easter: an introduction

More from this seriesCatholicism DemystifiedSee all 45 articles