In the high middle ages, what in the way of duties would a European crown prince be expected to perform?

by Glinting

If I were a crown prince in Europe around the era of knights, nobility and such - a young adult, or late teenager - what sort of duties would I have? How much in the way of responsibility would be bestowed upon me, and what would the nature of those responsibilities be? Administrative duties? Political ones? Or would I largely be focusing on education still?

Also, how would those duties change if the current monarch was ailing, and I was likely to take the throne sometime in the next few years?

I'm most interested in times of (relative) peace, since I imagine many of such duties would ordinarily be military-related, but what else?

Comrade-Chernov

Varies from realm to realm and from cultural norms to cultural norms of course, but typically as a crown prince one would be expected to be a (successful, obviously) military leader, a diplomat, an administrator or perhaps pupil to an important councillor, and married to an equally important noble from a neighbor that could be called upon in times of strife for aid. If the monarch was ailing, then potentially even a regent, taking upon the more active or strenuous tasks while the de jure leader handled the less intensive, mundane tasks.