Warfare was the raison d’être of medieval knights. Whatever debates might have existed about the importance of courtliness, romantic love, or economic stewardship, late medieval chivalry prized warfare as its central component, idealizing prowess in battle as a valorizing achievement for which the warriors of Christian Europe ought continually to strive. Across Europe and throughout the High and Late Middle Ages, knights emulated the heroes of chivalric literature and history: Roland, El Cid, Judas Maccabeus, Godfrey de Bouillon; warfare was truly a knight's calling. Not all fighting was equally valorous, though. In the 14th century, the French knight Geoffroi de Charny outlined a hierarchy of various types of deeds of arms, each being more honorable than the last. Jousting and participating in tournaments (we might call them practice for war) are the first and second steps, certainly honorable pursuits, for they require physical strength, hardship, “crushing and wounding, and sometimes danger of death.” Above “practice war,” Charny declares that fighting in wars, whether for oneself, for one's family, or for one's lord, accrues great honor to a knight. He initially calls fighting in war the highest honor that a man can find in this world, “for it is from good battles that great honors arise and are increased, for good fighting men prove themselves in good battles.” Upon further reflection, Charny recognizes one particular form of warfare which is better than others, asserting that

For Charny, then, all war was positive and rewarding to a knight, but religious warfare was the highest good. We might expect that chivalry on the south side of the Pyrenees would look somewhat different; historians have convincingly argued that societies on the religious frontier in Iberia were often more tolerant of their Muslim neighbors than were their northern European neighbors, at least up until the second half of the 15th century.