During the late Middle Ages, unlike the first five centuries of the period, warfare in Europe was far from constant. Most conflicts were short and limited in scope—generally no more than picking off some property of a neighbor—and periods of peace were common.

Knights who looked to war for glory, adventure, or income had a hard time of it during times of peace. Representative of these unemployed warriors was the English knight and mercenary Sir John Hawkwood, who upon being wished peace by two friars, replied, "May the Lord take away your alms [donated money].... Do you not know I live by war and peace would be my undoing?" Thus, many knights welcomed the Crusades, the holy wars of the twelfth and thirteenth centuries that sent thousands of the mounted warriors to fight in the Near East.

Call to Holy War