The first fortification of the Old Town of Rhodes was Byzantine (7th century) and divided the town into three areas - the Acropolis, Kollakio (Upper Town) and Bourgo (Lower Town). During the domination of the island under the Order of the Knights of St. John, the walls were extended by 2/5. In the early 12th century the rectangular wall was extended by an area of 175.000 sq,m.
From 1309, when it was occupied by the Knights and became the administrative center of the knightly state, apart from the internal affairs of the new state, Rhodes had to face calls and threats from the Muslims. The strong walls resisted the siege of Mehmed II the Conqueror in 1480, resulting in the defeat of the Turkish power.
The medieval walls of Rhodes are approximately 5 Km long and 12 meters wide. They have turrets, a moat and Gates with drawbridges. The most important of the entry an exit gates of the Medieval Town are the Gate of d' Amboise and Thalassini Gate, known as the Port Gate.