From the first expedition for the liberation of the Holy Land, which was convened at Clermont (1085) and ended in Jerusalem (1099), the archetype of the crusade par excellence was constructed. The model was refined and underpinned by later canonists, who took it upon themselves to define the institution as a very specific type of warfare: a “holy war” because of its orientation towards the defence of the Church and Christianity, which could only be proclaimed by the Pope, whose participants recognised themselves as crusaders/crucesignati by means of certain symbolic elements or by taking a vow, and which was associated with a series of spiritual and temporal privileges, which could only be guaranteed by the pontiff as a form of remuneration for a service. On the basis of these elements, the perception that emerges from the phenomenon is that it responds to a plurality of practical manifestations that can be perceived over time and space in different scenarios.