Final answer:
After the 4th Crusade, the focus of crusading shifted from primarily religious aims to more political and personal agendas, which led to broader campaigns against a variety of enemies and a decline in traditional crusades to the Holy Land by the late Middle Ages.
Step-by-step explanation:
The notion of crusading underwent significant change after the 4th Crusade, shifting from its original aim of reclaiming the Holy Land to encompass broader objectives driven by political and personal agendas. The Fourth Crusade resulted in the diversion of the crusade to Byzantium rather than Jerusalem and led to the infamous sacking of Constantinople in 1204. This event realigned the purpose of crusading, focusing less on the liberation of the Holy Land and more on a variety of objectives including the pursuit of land, wealth, and resolving internal Christian conflicts.
In the wake of these changes, subsequent crusades saw a wider scope of targeted campaigns driven by the papacy, such as those against heretics, rivals, and non-Christians even outside the Middle East. As the frontline of crusading activities shifted, enthusiasm for traditional crusading to the Holy Land declined. By this point in history, the notion of crusading had evolved into a broader instrument to be wielded in the complex landscape of medieval politics and power struggles.