No significant information nor remains have survived to illustrate the Byzantine settlement that succeeded the ancient city. Nor do we know much about the first years of the Latin conquest. From the beginning of the 14th century, however, the history of Kastro is linked to that of the Catalan Da Corogna family that settled on the island in 1307. In the ‘Mesa Kastro’, there still survives to now (in the family Stavrianou’s house) an embedded marble octagonal column with a Latin inscription mentioning the name of Giannoulis da Coronia and the date MCCCLXV (1365). It has been argued that the medieval settlement was fortified in 1374. In any case, the capital of Siphnos was already fortified by the early 15th century, as shown by a map by C. Buondelmonti. The Gozzadini (a Kean family, from Bologna) succeeded Da Corogna as the rulers, from 1465 until the Turkish conquest in 1537. As tax vassals then and later, until the definitive end of the Latin rule in 1617, they may have proceeded to make improvements to existing fortifications.
The defensive system adopted in Siphnos, as in other Cycladic islands, differs from the tradition of the fortification walls of antiquity. It is based on a row of close-packed houses, in rings or rectangles, arranged in such a way that they themselves form the defensive wall. The castle- houses gave onto the interior of the settlement and had only small openings to the outside world. The entrance proper to the settlement itself was controlled and secured through just a few gates.
In a dominant and naturally fortified position, the medieval settlement of Kastro consists of two defensive rings. The medieval wall, founded on the enclosure of the ancient acropolis, defines the Inner Castle/Mesa Kastro within its defensive ring. This is the core of the fortification complex, at the top of the hill, where the residence of the rulers was located. To its east, the mansions of the wealthiest families were built, with spacious halls, marble lintels and coats of arms. Here is also located the unique Latin church of Agios Antonios (Fragantonis), as well as the main Orthodox church of Panagia Eleousa, formerly the Metropolis. As the centre of the settlement and in the following centuries of the Turkish rule, the Mesa Kastro hosted the residences of the prelates in Konakia, as well as the Chancellery, but also the Despotika (residences and metropolitan offices). In 1646 all this was put in place by Patriarch Parthenios the Archbishopric of Siphnos.
With time, a second zone of houses developed around the first fortification core, on the three sides of the Inner Castle (to the west, south and east). In this outer ring, the houses are mostly smaller and on a narrow frontage and one-room wide, with two-storeys (as single-family houses). They were inhabited by poorer families. Following the morphology of the terrain, the settlement finally assumed an ellipsoidal shape with the major axis northwest to southeast. By 1629, judging from a depiction by R. Monnani, the settlement seems to have taken its definitive form.
A characteristic of Kastro, as of other similar defensive settlements, is the system of horizontal ownership (where each floor of the two-storey houses has a different family). This is also evident in the facades of the castle-houses: they have a separate entrance on each level and an external staircase for access to the one on the floor above.
Two arcades (loggias), that spring symmetrically from the ground floor of the castle-houses in the southern part of the outer enclosure, ensure access to the interior of the settlement, by leading to the main road of Kastro on the long axis of the ellipsoidal town-plan. The loggia on the northeast side of the settlement was perhaps the only entrance from the north. Internally, to enter the Inner Castle, there was another gate that does not survive today. The gates were closed with iron-barred doors, while the defence of the settlement was reinforced with towers.
Inside the settlement, the streets are narrow, free spaces were limited and there is no evidence of the existence of any deliberately planned square, apart from certain widenings that are always associated with a church. The economical use made of space seems to be behind the construction of the two- and three-story residential buildings. There does not seem to have been an organized commercial centre within Kastro; rather such was located in the nearby port of Seralia, to the south.
Later, from the 18th century, the settlement gradually expanded further to the south, and outside the second defensive ring. On both sides of the stepped path connecting Kastro with the villages, new one-level buildings began to be run up, housing craft activities or warehouses. In the following century, in the area ‘outside the Castle’, we also find olive presses, bakeries and other workshops.
The current settlement of Kastro is one of the most imposing and best-preserved medieval defensive settlements in the Cyclades, since it survived as an independent, distinct urban complex, which did not expand significantly beyond the original medieval core. The settlement largely retains its fortified building configuration. Inevitably, alterations have accrued (i.e. additions to the exterior of the castle-houses, such as large windows and balconies). These have come about on the one hand by the sheer unbroken nature of its habitation (let us not forget that Kastro was the capital of the island throughout time until 1836, when the administrative centre was transferred to Apollonia), and on the other hand by the tourist development of recent decades. The complete elimination of those factors that had imposed the fortified character on the settlement and the consequent change in the needs of the residents have played a role too.
bibliography SIPHNOS, ‘Melissa’ Publishing House, Athens 1982 SIPHNOS, Ministry of the Aegean, Athens 1998 Lina Dematha, Σχετικά με τα κάστρα-οικισμούς στις Κυκλάδες στη διάρκεια της Λατινοκρατίας. Το κάστρο της Σίφνου, Athens 1984 Simos Symeonidis, Ιστορία της Σίφνου από την προϊστορική εποχή, Athens 2014 Anastasia Tzakou, Κεντρικοί οικισμοί της Σίφνου. Μορφή και εξέλιξη σε ένα παραδοσιακό σύστημα, Athens 1979 Troullou, Maro Filippa-Apostolou, Το Κάστρο της Σίφνου. Αμυντική οργάνωση και οχυρωματικός χαρακτήρας, Armos, Aristotle University of Thessaloniki
