History of the Cyclades Roman province. Under Diocletian, there existed a “province of the islands” that included the Cyclades. Christianisation seems to have occurred very early in the Cyclades. The catacombs at Trypiti on Milos, unique in the Aegean and in Greece, of very simple workmanship, as well as the very close baptismal fonts, confirms that a Christian community existed on the island at least from the 3rd or 4th century. From the 4th century, the Cyclades again experienced the ravages of war. In 376, the Goths pillaged the archipelago. When the Roman Empire was divided, control over the Cyclades passed to the Byzantine
History of the Cyclades Empire, which retained them until the 13th century. At first, administrative organisation was based on small provinces. During the rule of Justinian I, the Cyclades, Cyprus and Caria, together with Moesia Secunda (present-day northern Bulgaria) and Scythia Minor (Dobruja), were brought together under the authority of the "quaestura exercitus" set up at Odessus (now Varna). Little by little, themes were put into place, starting with the reign of Heraclius at the beginning of the 7th century. In the 10th century the theme of the Aegean Sea was established; it included the Cyclades, the Sporades, Chios, Lesbos and Lemnos. In fact,