The centuries that followed were marked by the presence of foreign conquerors. After a short occupation of the island by the Venetians and the Genoans, Kos came under the control of the Ioannite knights in 1314. The Order was a force to be reckoned with,
with its own governors, who were constituted by the Council of the knights of Rhodes. At the same time Kos was attacked by the Turks. The knights however successfully managed to repulse them for a time largely due to the fortifications of the Perimeter Wall and the Castle of Nerazia (city), the Castle of Antimachia, which was unsuccessfully attacked - mostly in 1457, the Castle of old Pyli and the Castle of Kefalos. Even today the restorations to the damage done by the Turkish attacks of the two most important castles, those of Nerazia and Antimachia, are clearly visible.