After the Fourth Crusade, and the taking of Constantinople by the Crusaders in 1204, the Cyclades came under the control of the Venetian Republic and the so-called Duchy of the Archipelago was formed.
Marco Sanudo was the Duchy’s first duke when it was created in 1207 and awarded ‘fiefdoms’ to other Venetian nobles, with Santorini coming under the control of Giacomo Barozzi. The Barozzi family built the 5 fortresses of the island at Skaros, Oia, Pyrgos, Emborio and Akrotiri. Ironically, the ‘capital’ and centre of administration for the island was the fortress of Skaros, of which, little remains today.
The Barozzi family controlled Santorini for 128 years from 1207 to 1335 when they were deposed by the then Duke of the Archipelago, Nicholas I Sanudo.