Hogwarts castle was not built by the founders, nor was it originally built to house a school. Castle building technology did not arrive in Britain until after the Norman Conquest in 1066. The founders most likely set up their “school” in a large town called Hogwarts, which had already existed in one form or another for millennia.
Hogwarts castle must have been built long after the founding for the defence of the town called Hogwarts and continued to be used for military and political purposes for many centuries afterward before it came to house the modern Hogwarts School.
- When Hogwarts was built
- How it lead to the founding of Hogsmeade
- What purpose the castle was used for before it became a school
- Why it contains something as powerful as the Room of Requirement