after the refusal by the Knights to pay,they began systematic attacks on the island, forcing the residents to leave many times and seek refuge in the castles. After the take over of Rhodes by the Ottomans in 1522, Kos along with other islands of the Dodecanesse pass into the Sultans hands. The economy of the island depends on agriculture and commerce from the harbour. The Castle Neratzia is a safe commercial stop for ships.