Final answer:
In medieval castles, the person responsible for training hawks for hunting was the falconer, who occupied a prestigious role within the castle's social hierarchy.
Step-by-step explanation:
The person in medieval castles who trained hawks for hunting was known as a falconer or hawker. Falconry was a popular sport and status symbol among the medieval nobles. The falconers held a prestigious position within the castle hierarchy, taking care of and training birds of prey like hawks and falcons for hunting small game. This practice, steeped in tradition, dates back to ancient times and was as much a social activity as it was a means of procuring food.