The study of the uses and meanings of the word “crusade” in the Middle Ages is aimed at bettering our understanding of how the crusading movement was perceived and conceptualized by contemporaries. Although the word “crusade” remained uncommon in medieval texts, it existed and was used in a large number of European languages from the first decades of the 13th century. By assigning the word “crusade” to a phenomenon, contemporaries created a mental category which connected different realities together and differentiated them from others labelled differently (“wars”, “pilgrimages”, etc.). Since military expeditions to Jerusalem were considered, in the Middle Ages, as the most holy of enterprises, the word “crusade” was very often used as a legitimizing tool to promote or justify a large variety of undertakings: a military expedition against enemies of the faith, but also a papal indulgence letter or a royal tax. Defining the crusading movement was both a way to understand it better and to promote a specific understanding of it, often linked to the defense of specific political interests.
As a consequence, not every speaker had the same conception of what a crusade was, and enterprises labelled “crusade” by some authors were denied this term by others. The comparative study of the uses of this word thus reveals competing views on the crusade: with semantics ranging from discussions on the legitimacy of crusading against the so-called heretics inside Christendom, to competitions between popes, emperors and kings for supremacy over the crusading movement, to opposition to new forms of taxation imposed in order to finance these wars against the enemies of the faith.
The crusading movement thus appears as much more complex and nuanced than is usually assumed. Studying the competing uses of the word “crusade” also helps us to better understand its modern uses, as well its particularly large current polysemy. It shows how words do not always provide a simple description of reality, but can also represent complex processes of semantic construction of which everyone of us should be aware. The use of “crusade” by Eisenhower in 1944, by G.W. Bush in 2001 or in ISIS propaganda in 2016-18 can therefore be explained not as “misuses” of the word but as fitting into a long history of similar usage in order to promote specific ideologies.