Origins
The Knights Hospitaller — formally the Order of the Knights of the Hospital of Saint John of Jerusalem — were founded around 1099 at the time of the First Crusade to operate a hospital for pilgrims to Jerusalem. The hospital had existed in some form since approximately 1023 (founded by merchants from Amalfi), and was operating in the Muristan district of Jerusalem when the Crusaders captured the city.
The original Hospitallers were a fraternity of lay brothers who lived under monastic discipline and provided medical care. Around the 1130s, under the master Raymond du Puy, the order added a military function — armed escort for pilgrims and participation in the defence of the Crusader states. By the mid-12th century the Hospitallers were one of the two major Crusader military orders (alongside the Knights Templar, founded around 1119).
In the Holy Land
The Hospitallers built and garrisoned several of the most important Crusader fortresses, including Krak des Chevaliers in modern Syria (one of the best-preserved medieval castles in the world). They maintained extensive hospital operations: the main hospital in Jerusalem treated approximately 2,000 patients at a time, the largest medical facility in the medieval Mediterranean.
After the Crusaders lost Jerusalem to Saladin in 1187, the Hospitallers relocated to Acre on the Mediterranean coast. When Acre fell to the Mamluk Sultan al-Ashraf Khalil in May 1291, the Crusader presence in the Holy Land ended. The Hospitallers regrouped on Cyprus.
Rhodes, 1310–1522
In 1306–1310 the Hospitallers conquered the island of Rhodes from the Byzantine Empire and established it as their independent base. They ruled Rhodes as a sovereign state for the following 212 years, defending Christian shipping in the eastern Mediterranean and conducting regular naval warfare against the expanding Ottoman Empire.
The Hospitallers built substantial fortifications across their Aegean territories. The fortress at Bodrum on the Anatolian mainland, the Castle of St Peter, was constructed between 1402 and 1522 using stones quarried from the ruins of the ancient Mausoleum at Halicarnassus. The Hospitaller decision to demolish one of the Seven Wonders of the Ancient World for building material is one of the more striking acts of cultural recycling in European history.
The Hospitallers also dismantled what remained of the Colossus of Rhodes’s pedestal and incorporated the marble into the harbour fortifications of Rhodes town.
After a five-month siege by Sultan Suleiman the Magnificent in 1522, the Hospitallers surrendered Rhodes on terms. Approximately 7,000 surviving Knights and Greek civilians were allowed to evacuate. The Hospitallers spent the following eight years searching for a new base.
Malta, 1530–1798
In 1530 the Holy Roman Emperor Charles V granted the Hospitallers the island of Malta as a hereditary fief in exchange for a nominal annual rent of one Maltese falcon. The Hospitallers ruled Malta for 268 years, building substantial fortifications (most spectacularly the harbour city of Valletta, founded after the Great Siege of 1565 in which 600 Knights successfully held off a Turkish force of approximately 30,000), maintaining a substantial navy, and continuing their original hospital function.
Malta fell to Napoleon Bonaparte in June 1798 during the French expedition to Egypt. The Hospitallers were expelled. Most of their accumulated wealth was confiscated.
The modern Order
The Order survived the loss of Malta in attenuated form. It relocated to Rome in 1834 and operates from there to the present day under the name Sovereign Military Order of Malta. It is recognised by approximately 110 countries as a sovereign subject of international law (despite having no territory) and runs a substantial international humanitarian operation, primarily through Malteser International, which provides emergency medical aid in conflict and disaster zones. The Order’s membership is approximately 13,500 worldwide; the Grand Master is elected for life.
The Order’s official residence in Rome is the Palazzo di Malta on Via Condotti. The Maltese eight-pointed cross — the historic symbol of the Hospitallers — remains the Order’s emblem.