In the first years of Venetian rule, the new masters of the town made do with the Byzantine defensive walls they found upon their arrival, limiting their activities to modifications, improvements and repairs to the enceinte and gates. These were carried out so as to bring the fortifications into line with Western standards and afford protection from internal unrest. On top of the earthworks the Venetians constructed a revetted, inclined curtain wall studded with escutcheons, ending in a characteristic cordone (semicircular stone cornice).

Particular attention was paid to the harbour area and seafront walls - new sections of defences were built and two new gates added.