In modern Greece at least one legacy remains of the Crusaders’ sack of Constantinople in 1204 and their subsequent occupation of Greece: Most Catholics in Greece — some 50,000 people — are Latin. However, as many as 2,500 people share the rites of the dominant Orthodox Church and are in full communion with the pope.

No larger than a typical North American suburban parish, this Eastern Catholic church is sui juris, or autonomous, within the Catholic communion of churches and is led by two apostolic exarchs, based in Athens and Istanbul, respectively. If not for the humanitarian and pastoral works of one of its leaders, Bishop George Calavassy (1920-57), this church would barely merit a footnote in the annals of church history.

Origins. As the Romans consolidated their gains in the eastern Mediterranean in the first century, Christianity took root in the Greek-speaking world. The apostle Paul’s work among the Colossians, Corinthians, Ephesians, Galatians, Philippians and Thessalonians is well documented. Whether in the Roman provinces of Achaea, Epirus and Macedonia or in the communities of greater Greece, these Greek-speaking Christians formed churches that developed into important centers of the faith.

An integral part of the Greek world, these Christians provided the philosophical foundation and theological vocabulary that helped define the teachings of Jesus among non-Jews. As this church grew throughout the empire, a distinctly Greek school of theology developed alongside a Syriac school dominant among learned Semitic Christians.

Often characterized as cosmopolitan, the Greek school eventually asserted its preeminence when the Roman emperor, Constantine I, moved his government from Rome to Byzantion in the year 330, christening the small Greek port, “New Rome.“ This new imperial capital took on a distinct Christian identity, particularly after Emperor Theodosius I established Christianity as the state religion of the Roman Empire in 394.

While the power of old Rome waned, New Rome grew. The Christians of what is now Greece, though technically under the authority of the pope in old Rome, gravitated to the culture, church and liturgy of New Rome, popularly called Constantinople. These liturgical rites, which originated in the Syrian city of Antioch but after the sixth century matured in Constantinople’s Great Church of the Haghia Sophia, are now commonly referred to as Byzantine.

Byzantine Greece. After the Arabs seized the Egyptian city of Alexandria in 641, the Greek city of Thessalonica assumed cultural, ecclesiastical, economic and political prominence second only to Constantinople. Two sons of the city, Cyril and Methodius, were charged by the head of the Byzantine church, the ecumenical patriarch, to work among the pagan Slavs to the north. The brothers created a distinct alphabet, translated Scripture and transcribed the liturgy into Slavonic. Eventually, their ministry (and that of their successors, Sts. Clement and Naum) won the Eastern Slavs to Christianity in its Byzantine form.

Yet it is in Greece’s medieval monasteries — Daphni, Hosios Lucas, Mount Athos and Nea Moni — where the richest concentration of Greece’s Byzantine legacy survives. Founded during the empire’s zenith (10th to 12th centuries), the churches, refectories and treasuries of these foundations house some of the greatest works of what is now called Byzantium. Long after its collapse, monks kept it alive, commemorating in their liturgies and prayers emperors and empresses, saints and scholars, iconographers and philosophers.

Greece’s position in Byzantium grew in the 11th century as the Seljuk Turks overran Anatolia, which had once provided the empire with grain, soldiers and tax revenue. The heartland of the Greek world prospered, providing markets with grain, oil and wine as it filled the coffers of the imperial treasury with revenue. But this financial success, coupled with dynastic chaos in Constantinople, eventually proved its downfall.

Relations between Byzantium and Latin Europe had never been strong. The papal coronation of Charlemagne as Emperor of the Romans on Christmas Day in the year 800 incensed the Byzantines, whose emperors identified themselves as Romans. Relations eroded further as Charlemagne’s successors, buttressed by the papacy, seized parts of Magna Graeca — Sicily and southern Italy — which historically belonged to Byzantium.

Disputes between the heads of the churches of Constantinople and Rome exacerbated relations between the Christian East and the Christian West. But the Great Schism of 1054, in which the ecumenical patriarch and the pope excommunicated each other, definitively severed full communion between the churches, thus drawing a faithline through the ancient Roman prefecture of Illyricum, of which modern Greece was a part.

Using the schism as justification, Catholic Norman knights sacked Thessalonica in 1185. Bands of Latin Crusaders commissioned to recapture the Holy Land from the Muslims — financed by the merchant city-states of the Italian peninsula — threatened other Byzantine cities with the same. In 1204, the Crusaders stormed Constantinople, the greatest prize of all, looting its palaces and churches, even desecrating the Great Church of the Haghia Sophia.

Byzantium collapsed in the ensuing confusion. Greek city-states — some ruled by exiled members of the Byzantine imperial family, others by Crusader knights — sprouted and vied for control of commerce and territory. This Latin occupation of Byzantium deepened the schism between the Orthodox East and the Catholic West and did not evaporate after the Latin occupation of Constantinople ended in 1261.

Greek Catholics. Despite a renaissance in the arts, learning and spirituality, a revived Byzantium failed to reclaim its power and awealth. And church councils held in 1274 and 1439 failed to heal the breach between Catholics and Orthodox. Meanwhile, as Genoese, Pisan and Venetian bankers purchased properties and privileges from cash-poor emperors, the Ottoman Turks conquered what remained of Byzantine-controlled lands in Greece. Eventually, only a few fortified castles and the city of Constantinople remained.

After Constantinople’s fall to the Ottoman Turks in May 1453, the sultan recognized the Orthodox ecumenical patriarch as the leader of the Ottoman Empire’s ethnic Greeks, or millet. Charged with representing the empire’s Greek community and keeping it in line, the ecumenical patriarch exercised spiritual and temporal leadership. Assuming the trappings of the last Byzantine imperial dynasty (including the use of the double-headed eagle, the personal insignia of the emperors), the patriarchs worked to preserve the Orthodox identities of their people.

After the collapse of Byzantium, a significant number of Byzantine Greek notables fled to Italy, where popes and dukes alike offered refuge and support. In 1576, Pope Gregory XIII founded the Greek College for those men interested in studying for the priesthood. Initially staffed by some of the leading Greek intellectuals of the late Renaissance period, the college encouraged many of its students, most of whom were Greek Orthodox refugees, to work for the restoration of church unity. While many individual Orthodox hierarchs and scholars entered the Catholic Church, attempts to form an Eastern Catholic church from the Greek Orthodox community failed.

During the Greek war of independence in 1829, the Ottoman sultan restricted the civil and spiritual authority of the ecumenical patriarchate. By doing so, he opened the way for the formation of a Greek Catholic community in Ottoman Turkey. A few decades later, a Latin priest from the Greek island of Syros, John Hyacinth Marangos, formed a small group of Greek Eastern Catholics in Constantinople. This included two bishops originally of the ecumenical patriarchate who converted to Catholicism, Meletios of Drama and Benjamin of Neapolis. Another convert, Father Polycarp Anastasiadis, continued the work after Father Marangos moved on to Athens in 1878.

In 1895, Pope Leo XIII encouraged the French Assumptionists, who were active in forming an Eastern Catholic church in Bulgaria, to do the same in Constantinople. In addition to their studies on the Eastern churches, the Assumptionists worked with the struggling Eastern Catholic community and later founded a seminary and two small parishes.

In 1911, Pope Pius X erected an ordinariate, later an exarchate, for this nascent church and named Father Isaias Papadopoulos as its first bishop. Called to Rome during the waning days of World War I, he was succeeded in 1920 by Bishop George Calavassy, who witnessed firsthand the horrors of a country at war with outsiders and with its own Christian minorities.

Call of the East. By 1920, an estimated million refugees had swarmed Constantinople. Hundreds of thousands of them were Greeks. Fleeing the excesses of the Bolsheviks, some 100,000 penniless Russians engulfed the former Byzantine capital. Scores of Armenians, Assyrians and Chaldeans fled their homesteads during and after the war; many more died in the struggle to defend them.

Among the first to minister to the needs of the dispossessed was Bishop George. Overwhelmed by the refugee crisis — especially after his requests for funding in Europe and the United States went unanswered — the bishop appealed to Father Paul Wattson. The founder of the Franciscan Friars of the Atonement exhorted the readers of his monthly publication, The Lamp, to support the bishop’s relief efforts. In 1922, Father Paul also enlisted the help of Msgr. Richard Barry-Doyle, a British chaplain who worked with the city’s English-speaking Catholic community and a tireless advocate for the Russian refugees.

The three men banded together, creating a Million Dollar Fund in the United States to raise money for Bishop Calavassy’s orphanage, school and church, which the bishop had moved to Athens later that year. Msgr. Barry-Doyle’s “Call to the East“ raised considerable sums and in 1924, with Father Paul, he formed “The Catholic Near East Welfare Association,“ which in its original form supported the humanitarian and pastoral activities of the Eastern Catholic Exarchate in Athens and Constantinople.

Pope Pius XI recognized the value of the new association and in 1926 merged it with another, the Catholic Union, to form the Catholic Near East Welfare Association. The pontiff expanded its mandate to support the activities of the Christian East and to work toward Christian unity, active concerns of both Bishop Calavassy and Father Paul.

In 1932, the Holy See divided the exarchate into two and appointed Dionisios Varoukhas as bishop in Constantinople, which had been renamed Istanbul. Bishop Calavassy remained in Athens, where despite the hostility of the Orthodox hierarchy, he continued his works of charity among the poor, founding a hospital in Athens, a school for handicapped children in Nea Makri and the Pammakaristos Sisters of the Mother of God, who administered these first-class institutions.

Today. The number of Greek Eastern Catholics remains tiny; perhaps 50 remain in Istanbul, where the exarchate functions without a resident priest. However, the cathedral in Athens, dedicated to the Holy Trinity, has become a hub of activity for the city’s Iraqi Christian refugee community, most of whom are Chaldean Catholics. In the last 20 years, Athens has also attracted a number of Romanian and Ukrainian Eastern Catholic workers, who now attend regularly scheduled liturgies at the neo-Byzantine church.

The Orthodox Church of Greece remains hostile to the existence of this church, “which it views as a gratuitous creation of the Catholic Church in Orthodox territory,“ writes Paulist Father Ronald Roberson. In 2008, Pope Benedict XVI appointed a leading canonist and ecumenist, Bishop Dimitrios Salachas, as apostolic exarch in Athens. A member of the international Orthodox-Catholic theological dialogue, the bishop’s greatest challenge remains domestic and concerns not just the position of his tiny church, but its very existence.

Michael La Civita is CNEWA’s vice president for communications.