ABSTRACT
This chapter examines how fixed fortified points on the islands of Chalki, Symi, Tilos and Nisyros. The strategic importance of these four islands was that they helped control the sea-lanes to the second most important territory of the Knights, the island of Kos, as well as providing early warning of potential enemy ships that might threaten Rhodes itself. The castles of Chalki and Alimnia were constructed by the Knights on Hellenistic foundations. Both have been well surveyed by Gerola. Palaiokastro is the most formidable and impressive Hellenistic fortresses to be encountered in the whole of Greece. Situated on the north-west coast, it was constructed exclusively of basaltic andesite, one of the hardest rocks of the world. The Knidos peninsula is the nearest part of the Turkish mainland to Tilos, 20 kilometres away to the north-east. The island of Tilos, though fertile with rich volcanic soil, has seen its inhabitants largely abandon agricultural pursuits.
