According to the Knights Hospitallers’ own foundation legend, their origins went back to a time before the Crusades and even before Christ. They held that their original hospital in Jerusalem had been founded by the Seleucid Antiochus III in the third century BC. The real origin of this order of fighting churchmen was more recent and more obscure, but it seems that the original hospitals were established by Italians in Jerusalem and Antioch a few decades before the First Crusade arrived in Syria in the late 1090s. In the early years of the Kingdom of Jerusalem and the other Crusader palatinates, the Hospitallers confined their mission to caring for the sick and sheltering pilgrims, but slowly they were also drawn into providing armed defence for pilgrims to Jerusalem and elsewhere. By 1136 at least it is clear that they had assumed a military role and for more than a century and a half they would rival the Knights Templar in military, political and economic importance. They built and garrisoned vast castles, particularly in northern Syria – notably Crac des Chevaliers and Margat. They were one of the pillars of the Kingdom of Jerusalem and, when the army of the kingdom was defeated at Hattin in 1187, Saladin singled out the Hospitallers and the Templars for execution by a gang of murderous Sufis. Nevertheless, despite their commitment to holy war, the Hospitallers also remained dedicated to caring for the sick, so that the history of the order was pervaded by tensions between those who wished to give priority to charitable activities and those who were more committed to fighting.

From the Enlightenment onwards the Crusades have received a bad press from historians. Steven Runciman concluded his three-volume A History of the Crusades (1951–4) with these words: ‘High ideals were besmirched by cruelty and greed, enterprise and endurance by a blind and narrow self-righteousness, and the Holy War itself was