Founded in Jerusalem in 1070 to operate a hospital for pilgrims, the Order of the Hospital had transformed itself over the next two centuries into one of Christendom's most effective military religious orders. The Fall of Acre in 1291 ended the Crusader states and forced the Knights to retreat to Limassol on Cyprus, where they spent two unhappy decades clashing with King Henry II and watching European powers debate whether to confiscate the property of military orders that no longer had Holy Lands to defend. Foulques de Villaret, elected Grand Master in 1305, started planning a base of his own. Rhodes belonged to a Byzantine Empire too weak to hold it. With Genoese mercenaries and a small force of 35 Knights, six Levantine cavalry, and 500 foot soldiers, Villaret took the island in 1310 after a long fight for the citadel. The Hospitallers spent the next 134 years turning Rhodes into the strongest Christian fortress in the eastern Mediterranean.

Aynal Gecut started the campaign on Kastellorizo, a small Hospitaller outpost halfway between Rhodes and Cyprus, where his men razed the castle before sailing on. On August 10, 1444, his 85 ships appeared in the channel between Rhodes and the Anatolian mainland. The Mamluks landed on the northwest coast, north of Trianta, without resistance. They captured positions adjacent to the Rhodes citadel and opened fire with arrows. The defenders shot back from the walls. The Mamluk artillery focused the next day on the western flank near the gate of Agios Antonios, which the Knights themselves had identified as poorly defended. A second Mamluk column attacked the Mandraki harbor on the east, destroying ships at anchor and inflicting heavy casualties on Hospitaller sailors caught onshore.

Once the gate of Agios Antonios held against the artillery and the Knights had reorganized, Grand Master Jean de Lastic ordered a counterattack at Mandraki. French and Catalan Knights pushed the Mamluks out of the harbor area, killing many and forcing the rest to flee. The fighting paused for a stretch while both sides reorganized. On September 10, the Hospitallers attacked the Santa Maria outpost southwest of Agios Antonios. Heavy fighting followed, and the Mamluks eventually withdrew, taking their dead and wounded with them. By this point Aynal Gecut had concluded that the position was unwinnable. On September 13, the Mamluks struck their tents and lifted the siege, contrary to direct orders from Sultan Jaqmaq. They marched back to their original landing point at the northwest coast and began embarking.

Jean de Lastic proposed a sally to disrupt the embarkation, fall on the Mamluks while they were divided between ship and shore, and inflict another defeat to make the lesson stick. His military council rejected the plan. The Knights lacked the manpower to risk it; if even part of the sally went wrong, the loss could be irreplaceable. They watched from the walls instead. By September 18, the last Mamluk troops had embarked, and the fleet sailed for Asia Minor. Aynal had failed to take Rhodes, failed to break the Hospitaller blockade of Mamluk shipping, and failed his sultan's instructions. He had also, however, brought most of his force home alive, which 36 years later, in 1480, was more than the next attacker would manage.

The 1444 siege seemed at the time to confirm the strength of Hospitaller Rhodes. Grand Master Jean de Lastic had defended his island. Allies including Alfonso V of Aragon, the Duke of Burgundy Philip the Good, and Pope Eugene IV had supplied the auxiliary ships and provisions that helped the Knights weather the attack. The fortifications had been tested and held. But the larger geopolitical picture was already shifting in ways the siege did not change. The Fall of Constantinople in 1453, less than a decade later, would expand Ottoman power dramatically. The 1480 siege under Mesih Pasha would test Hospitaller defenses far more severely and just barely fail. The 1522 siege under Suleiman the Magnificent would succeed, ending Hospitaller Rhodes after two centuries. Each siege built on what its predecessors had taught both sides. The 1444 fight, modest in scale next to what came later, was the first lesson: that even a substantial Mamluk expedition could break against the walls and sail home empty-handed if the Knights kept their nerve.