The Order of St John of Jerusalem began as a hospital for sick and poor pilgrims and became a military order rivalled only by the Templars — nurses and knights at once. Unlike the Templars, it survived the fall of the Holy Land, reinventing itself as the sovereign naval power of Rhodes and later Malta, and it endures today as the Sovereign Military Order of Malta.
The Knights Hospitaller were unique among the military orders in doing two things at once: running the greatest hospital in the medieval world and fielding an army of warrior-monks. Founded in Jerusalem before the First Crusade to care for sick pilgrims, they militarised in the 12th century and became, alongside the Templars, the backbone of the Crusader states’ defence.
Where the Templars were destroyed, the Hospitallers adapted. After the Holy Land was lost they conquered Rhodes and ruled it as a sovereign order, then moved to Malta, and they survive to this day as the Sovereign Military Order of Malta — the only medieval military order with an unbroken existence.
Around 1080, merchants from Amalfi founded a hospital in Jerusalem dedicated to St John the Baptist, to care for poor and sick pilgrims. When the First Crusade took the city in 1099, the hospital and its rector, the Blessed Gerard, won fame and endowments across the new Latin kingdoms.
In 1113 Pope Paschal II recognised the community by the bull Pie postulatio voluntatis, freeing it from local control and placing it under papal protection. At this point it was still a purely charitable brotherhood — the sword came later.
Under Raymond du Puy, who led the order from around 1120, the Hospitallers took on a military role, escorting pilgrims and then garrisoning castles against Muslim armies. Raymond gave the order its Rule and reorganised it into a body that could both nurse the sick and wage war.
The dual mission was never dropped. Even at the height of their military power the brothers maintained their great hospital, and the care of the sick remained, in principle, the order’s first purpose.
A Grand Master governed the order for life. Beneath him served knight-brothers of noble blood, sergeant-brothers, and chaplain-brothers, later grouped by language into “langues”. The estates of Europe — organised in priories and commanderies — funded the war in the East.
At the heart of it all stood the hospital in Jerusalem, which could hold up to two thousand patients and treated pilgrims of any faith. The brothers addressed the sick as “our lords the sick”, a reversal of rank that expressed the order’s founding ideal of service.
The Hospitallers became master castle-builders, holding a chain of fortresses that no local lord could have maintained. The greatest was Krak des Chevaliers, granted in 1142 and rebuilt into the most formidable castle of the age; Margat (Marqab) guarded the northern coast.
These strongholds turned the order into a permanent, professional garrison for the Crusader states — a standing defence in a world where crusading armies came and went with the seasons.
The Hospitallers fought in every great crisis of the Latin East. Their master Roger de Moulins was killed at the skirmish of Cresson in 1187, weeks before the order was annihilated with the Templars at the Battle of Hattin. At the Battle of Arsuf in 1191 it was a Hospitaller charge from the rearguard that broke Saladin’s pursuit and handed Richard the Lionheart his victory.
Disaster returned at La Forbie in 1244, where the order’s field army was destroyed. Baybars took Krak des Chevaliers in 1271, and when Acre fell in 1291 the wounded Grand Master Jean de Villiers was carried aboard ship as the city was overrun. With the mainland gone, the order withdrew to Cyprus.