Despite a considerable historiography on the crusades, there are still flickers of division among historians as to the definition of a crusade, or rather, divisions as to when all the features of a crusade became established. The First Crusade suffers the most from this tendency. Although it was the first campaign of its kind which historians agree to be definable as a ‘crusade’, the campaign of 1096–9, like many ‘firsts’, did not have all of the features of a crusade in a fully developed form. For example, the indulgence, which became a defining characteristic of the crusades, was in all likelihood not legally established or universal until almost fifty years after its origins were mooted at the Council of Clermont. Some of this tension arises because modern terms to define a crusade come with accumulated inferences and meanings which are anachronistic when applied retrospectively. The term ‘pilgrimage’ is such a contentious term, given its implications of an unarmed endeavour, and it is often qualified. The crusade was, therefore, an ‘armed pilgrimage’ or a ‘crusade-pilgrimage’ the crusaders were ‘warrior pilgrims’. Although a seemingly contradictory impulse, the term ‘pilgrimage’ became associated with the crusade because the Latin peregrinatio was frequently used by contemporaries for these expeditions.