Four visitors are known to have ventured over to Sokastro and recorded their casual observations. In 1843 Ludwig Ross noted vaulted chapels which he believed were ancient tombs and a castle which seemed to be medieval. In 1903, Richard Dawkins visited the remains and immediately noted the large number of cisterns and tumbled walls. He suggested that Sokastro had been built by the Franks but offered no evidence for his conclusion. 

Twenty years later in 1923, Gilbert Bagnani visited the site. He too noted the large number of cisterns, especially the very large one at the north edge. Similar to Dawkins’ observation and again without providing supporting evidence, Bagnani concluded that the fortified settlement was Frankish rather than Byzantine.  

Sometime prior to his publication in 1977, Nicholas Moutsopoulos and his students also visited Sokastro. He dated the surface ceramics to the 8th to 10th centuries although he neither described his survey strategy nor presented comparative sherds from sites elsewhere. They found no trace of an organized settlement, square or church, and concluded, possibly from the ceramic dates, that, “it was only a pirate haven” that served as a naval base for the Saracens of Crete. He also thought the entire settlement was abandoned abruptly because they observed no signs of remodeling and additions among the many buildings.

So far preliminary analysis of the ceramic evidence from the surface survey conducted in 2011 by Michael Nelson, Amanda Kelly and Todd Brenningmeyer and myself suggests that the fortified settlement was inhabited from the 11th to the 13th centuries.

The lack of literary and epigraphic sources as evidence leaves the reasons for the fortification of Sokastro open to speculation, especially because while they do infrequently mention Karpathos in general they never seem to indicate the islet of Sokastro in particular. In the 10th century Karpathians contributed to the development of galley ships and, when Nikephoros Phokas was planning his naval attack to expel the Saracens from Crete in 960 AD, he had to rely on Karpathian sailors to pilot his ships from Ios to Crete. After his conquest, he built the Cretan fortress of Temenos, for which see most recently Byzantine Fortifications by Nikos Kontogiannis. In 1036 ships from the Kibyrrhaiot theme, which included Rhodes and Karpathos, destroyed an Arab fleet in the Battle of the Cyclades, effectively clearing the Aegean of pirates and pacifying it. Byzantine Admiral Doukas made use of Karpathos in planning his attack on the rebel governor of Crete a century later, c.1091 or 1093. The Greek name Sokastro means “inner fort,” but inside what is open to speculation.

In the 11-12th centuries, within the timeframe of the ceramic assemblage on Sokastro, Byzantium allowed her traders and naval ships to be replaced by Venetians. Italian merchants increasingly participated in the south-north trade route from Egypt to Constantinople in the twelfth century but their effective land presence was in commercial emporia in Constantinople and the Palestinian coast, not fortified settlements or bases.

The invention and use of the magnetic compass by the middle of the 12th century reduced sailing times considerably by facilitating sailing at night and accordingly reducing the number of required ports of call for replenishing the fresh water supply. If so, such an eventuality might account for a gradual falling into disuse of the cisterns at Sokastro.

After they captured Constantinople in 1204, the Venetians began centuries of Italian control of Crete and Karpathos. Much later maps indicate an island off the west coast of Karpathos where the name Sorzadori is located. This can be explained as the Venetian word “sorgitori,” a rare nautical term used to refer to harbors deep enough to drop anchor, mooring places or anchorages. (I am indebted to Prof. Domenico Pietropaolo of the University of Toronto for his assistance with the meaning of Sorzadori.) Although the two smaller harbors at Kato Leukos were shallow, the larger one to the north, traditionally called Frangolimnionas, or Frankish harbor, was sheltered from the north winds by the islet of Sokastro. If the cisterns were still usable, then Sokastro would have provided an added benefit.

Based on the foregoing data, as an explanation I am tempted to suggest the hypothesis that the cisterns and fortification walls on Sokastro were built to replenish Byzantine warships with water in preparations for a naval attack on Crete. Centuries later Venetian mariners were aware of the safe anchorage at Frangolimnionas. Only future excavations may settle the question of when they were built and by whom.