Despite our familiarity with violence legitimised by religion, the medieval crusades continue to perplex modern audiences. Since at least the Enlightenment, the notion of warfare as an act of Christian charity, of physical aggression as an obligation imposed by God, has struck a discordant note. For Christian believers wedded to the idea that their religion prescribes non-violence and turning the other cheek, for rationalists who deplore what they view as the excesses of fanaticism and for materialist sceptics who detect the camouflaging of greed, intolerance and imperialism, the crusades have assumed iconic status as evidence of the strangeness of the past.

Prime suspects in this court of condescension are the Knights of the Temple of Solomon, or Templars. Established by a small group of pious minor French noblemen in the aftermath of the First Crusade’s conquest of Jerusalem in 1099, the Templars acted as a private police force to protect pilgrims arriving from the west. Although laymen, they swore monastic vows of poverty, chastity and obedience. Providing corporate identity, emotional cohesion and legal protection, such religious lay confraternities were not uncommon at the time. Allying monasticism with a military function was, however. Although the western European notion of warfare as an acceptable or necessary means of defence and a way of establishing peace reaches back to the classical world, the Templars offered a new refinement of this. It reflected the emerging justifications for crusading and the militant religious mentalities of the warrior aristocracies of western Europe. The Templar model was soon copied.

Rapidly, the original band of knightly policemen developed into a significant religious institution, providing a standing army central to the defence of the crusaders’ conquests in Palestine and receiving official patronage. This included the grant as their headquarters of the Al-Aqsa Mosque in Jerusalem, which the invaders, eager