In 1207 Siphnos was under the jurisdiction of the Duchy of Naxos. Later, after vicissituses of various sorts, it came under the more stable sway of the Catalan family Da Coronia in 1307.

The settlement in the fortress (castro) of Siphnos is elipsidal in form because it follows the morphology of the land. It is defensive in character and still preserves the form of its mediaeval defensive system.

Two defense circuits along the western side are visible and on the outer line there are a considerable number of single houses. The Latin cathedral is in the centre and preserved nearby is the stele with the 14th century inscription of Giannoule da Coronia.