Final answer:
The Janissary Corps consisted of young boys who were taken from Christian villages, converted to Islam, and trained as elite soldiers directly serving the sultan.
Step-by-step explanation:
The Janissary Corps was comprised of individuals who started as slaves but were specifically selected and trained to become elite soldiers. The Janissaries were young boys taken from Christian villages in the Balkans through a system called devşirme or "gathering." They were then converted to Islam and taught to serve loyally only the Ottoman sultan. Cut off from any family ties, their unwavering loyalty was to the sultan, making them a dependable and powerful force within the Ottoman military structure. They not only served in battles but also played significant roles as the sultan's household guard. The Janissaries were crucial in many historical events, including the famous siege of Constantinople in 1453.