How far were the military religious orders involved in secular warfare? The vocation of the Knights Templar, Knights Hospitaller, Teutonic Knights, and similar medieval institutions bound them to fight in defense of Christians, to prevent injustice to Christians and to lay down their lives for their brothers. Hence modern scholars of the medieval military religious orders have argued that the Templars, Hospitallers, and Teutonic knights generally avoided involvement in secular warfare and any warfare outside their own vocation.

Yet there were also occasions when the military religious orders were physically involved in hostilities against Christians: not necessarily in battle, but in various forms of conflict. This article will examine some of these instances and discuss how the military religious orders saw their role in the West, asking whether the military religious orders’ role in “worldly” conflict was much more fundamental to their overall activity than previous studies suggest. The subject of religious orders’ involvement in secular warfare calls into question the division between the ecclesiastical and secular realms and how far these were divided in practice during the later Middle Ages; the relationship between the religious orders and wider society; and the difference between canonical theory and practice. However, before proceeding into detailed discussion, it will be useful to set out how these Christian institutions were founded, and to investigate their original purpose.

The military religious orders first appeared in the city of Jerusalem in the early twelfth century, in the wake of the conquests of the First Crusade. Their members took life-time monastic vows of poverty, chastity, and obedience, combining permanent religious vows and military activity within their religious vocation.