While Harry Potter author J.K. Rowling was in the process of writing book five, Harry Potter and the Order of the Phoenix, she published two fictional Hogwarts textbooks: Quidditch Through the Ages and Fantastic Beasts and Where to Find Them. A proportion of proceeds from the sale of these textbooks goes towards the Comic Relief charity.
These companion books have been republished numerous times since 2001, alongside The Tales of Beedle the Bard.