During the Knights’ era the fortifications were extended, modernized and continuously reinforced. A hospital, a palace and several churches were among the many public buildings constructed at that time, offering interesting examples of Gothic and Renaissance architecture. Én spite of the hostilities with the Ottoman Empire, sea trade was a source of wealth and the markets of the city were thriving. Under the Knights, the island had a period of prosperity and the relations between them and the local population was characterized by tolerance and often by close collaboration. Most of the streets of the Medieval Town coincided with those of the ancient city. The division of the town into two parts was retained. in Rhodes the Order kept a well-organized archive that included documents issued by its leadership, correspondence, notary acts, etc. The archive has survived and is found today in the National Library of Malta. It constitutes a valuable source of information for the period.

The city was divided into its two parts by an inner wall. The Northern part, known as Chastel, Chateau, Castrum, Castellum or Conventus, was the site of the Grand Master’s Palace, the church of the Knights, the Latin Cathedral, the Catholic Bishop’s residence, the various “tongues” quarters, the Knights houses, a hospital etc. The South part, known as ville, burgus or burgum was the area where the laymen lived and included the market, synagogues, churches and public and commercial buildings.

In 1309 the island was sold to the Order of the Knights Hospitaliers of Saint John of Jerusalem. The Order was established in the 12^th century in Jerusalem for the purpose of nursing pilgrims and crusaders, but soon enough it was transformed into a combat unit and acquired vast tracts of land.

Having retreated from Jerusalem and then Cyprus, the Order established its Headquarters on Rhodes, taking a leading role in the Eastern Mediterranean at this time.