The walled city of Rhodes occupies a harbor that connected the Aegean with routes to the eastern Mediterranean. Ancient and Byzantine defenses preceded the medieval enclosure, but its dominant form emerged after the Knights of Saint John established their headquarters on Rhodes in 1309. Having lost Acre in 1291, the military and hospitaller order made the island capital a fortified base. Walls, towers, gates, a palace, hospitals, churches, inns, arsenals, and houses expressed both crusading warfare and the administration of an international religious order.

The Knights organized themselves into linguistic and regional divisions known as tongues. Their inns lined the Street of the Knights in the Upper Town, leading toward the Palace of the Grand Masters. The Great Hospital, built mainly between 1440 and 1489, embodied the order’s charitable purpose as well as its wealth. The Lower Town contained merchants, artisans, residents, and numerous churches. Builders combined western Gothic forms with Byzantine and local traditions, producing an urban landscape that differed from contemporary cities in northern Europe.

Rhodes endured major sieges by Mamluk forces in 1444 and by Sultan Mehmed II in 1480. Artillery changed defensive design, prompting thicker walls, angled works, firing positions, and continual remodeling under successive grand masters. In 1522 Sultan Süleyman I besieged the city for six months. The Knights surrendered and departed in early 1523. Under Ottoman rule, churches became mosques, new religious and civic buildings appeared, and houses, baths, fountains, and commercial structures adapted the inherited fabric without erasing the medieval street plan.

Italy seized the Dodecanese in 1912. Italian administrators excavated, cleared, restored, and sometimes extensively reconstructed monuments to emphasize a medieval and Italianate past. The Palace of the Grand Masters, badly damaged by an 1856 explosion, was rebuilt during this period with substantial conjectural work. Bombing in the Second World War caused further destruction. Rhodes joined Greece in 1948. UNESCO inscribed the medieval city in 1988, recognizing both its Gothic ensemble and the later Ottoman layers that record continuous urban occupation.

The four-kilometer circuit of walls remains impressive, but it is neither wholly medieval nor unchanged. Byzantine foundations, Hospitaller masonry, Ottoman repairs, Italian interventions, and modern conservation coexist. The old town is also a living residential and commercial district, so tourism, traffic, altered building use, utilities, and development place pressure on ordinary houses as well as famous monuments. Its historical value comes from this layered survival: a port city repeatedly reshaped by military technology, migration, worship, imperial government, and modern heritage policy.