- This spell was cast by Charms Master Filius Flitwick to protect the boundaries of Hogwarts Castle from the Death Eater forces in the late hours of 1 May, 1998, prior to the Battle of Hogwarts that started at midnight the next day.
Latin Protego, "I protect", and Horribilis, "horrible , frightful, dreadful".
Behind the scenes
- In Harry Potter and the Deathly Hallows: Part 2, this spell is not used. However, the similarly named Protego Maxima is among the defences that are put up in the film.