1. Historical retrospection
Catholicism in the Cyclades goes back in the early 13th century right after the fall of Constantinople (1204) and the conquest of a large part of the Byzantine Empire by the Franks.
The Catholic community in the Cyclades was formed in three phases reflecting respectively three different periods: the arrival of a Roman Catholic population with the conquerors, the conversion of Orthodox notables into Catholicism in order to maintain their high social position, the conversion of wider groups spurned by economic and social motives, and finally the activity of religious orders.
The largest catholic communities were formed on the islands of Syros, Naxos, Santorini and Tinos. In some occasions, for example Syros, catholics were the majority of the population up to the 18th century. The demographic state changed favoring the Orthodox population during the years of the Greek War of Independence, when a large number of Greek-Orthodox refugees came to the islands from other areas (northeast Aegean islands, Asia Minor). In addition to this, the fact that the Greeks assumed power favored Orthodoxy in contrast to Catholicism. Nevertheless, even now Catholics are a large part of the island’s population.
2. The Catholics today
Nowadays, most of the Catholic population lives on the islands of Syros and Tinos. In the rest of the Cyclades, there are a few catholics on the islands of Naxos, Santorini and Mykonos.
The Catholic Church of the Cyclades consists of the Archbishopric of Tinos and Naxos, the bishopric of Syros and the bishopric of Thera (Santorini). The Archbishopric of Tinos includes the islands of Naxos, Paros, Antiparos, Amorgos, Tinos, Myconos and Andros and functions as a diocese of the Aegean with 3,000 members. The Bishopric of Syros, within the jurisdiction of which are the two churches and the Catholic cemetery of Milos, counts up to 8,000 members, while the bishopric of Thera has about 150.
The activities of the Catholic community in the Cyclades include various parts of the social life. On Tinos, summer camps are organized by Catholics, while there are also the pilgrimages of the “Devotion of the Sacred Heart of Jesus” and of the Virgin Mary at Vrysi. On Syros, the center of Cycladic Catholicism, operate numerous Catholic organizations and associations, as well as the Center of Historical Studies, located inside the building of the Archbishopric.
The composition of the population of the Cycladic islands, mostly of Syros and Tinos, has resulted to several mixed marriages. The Catholic Church acknowledges the rituals of the Orthodox Church, whereas the latter does not. However, despite legal and formal problems, the two churches can be "unified" with the performance of both matrimonial rituals. The Catholic ritual precedes that of the Orthodox Church. The newly wedded decide on the religion of their children. Finally, we should mention that the Catholic Church celebrates Easter on the same dates as the Orthodox Church, a fact that brings together in celebration Christians of both creeds.