History of the Cyclades 6th century BC). The Persians tried to take them during their attempts to conquer Greece. Then they entered into Athens' orbit with the Delian Leagues. The Hellenistic kingdoms disputed their status while Delos became a great commercial power. Commercial activities were pursued during the Roman and Byzantine Empires, yet they were sufficiently prosperous as to attract pirates' attention. The participants of the Fourth Crusade divided the Byzantine Empire among themselves and the Cyclades entered the Venetian orbit. Western feudal lords created a certain number of fiefs, of which the Duchy of Naxos was the most important. The Duchy was conquered
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,