Harry Potter anniversary quiz: 20 questions to test your knowledge

Today marks the 20th anniversary of Harry Potter and the Philosopher's Stone, the first book in J.K. Rowling's phenomenally successful series.

Since its publication in 1997, a box-office breaking film franchise has followed, but it’s the book series that most fans remain fiercely loyal to.

If you consider yourself a Potterhead, have a crack at our fiendishly difficult Harry Potter quiz and see if your knowledge of the books is “Outstanding” or “Awful”.