'I don't remember telling you to use a Shield Charm… but there is no doubt that it was effective…'
-- Severus Snape to Harry during Occlumency Lessons (OP26)
This spell creates a magical barrier that will deflect hexes thrown at the caster.
History and Notes
In 1484 in the town of Poppleton, the tyrannical Earl of Paunchley held a jousting match. He insisted that all the nobles for miles around must come to cheer him on at the tournament and "no excuse would be acceptable" for missing the event. But young Edmund Gaddlegate fell out of a tree that day and broke his leg, and his mother put him to bed. The Earl wouldn't hear of anyone staying home, so he dragged Edmund and his mother to the castle, and said the mother had to watch while her child was tied to a horse and forced to compete in the jousting. The other knights left the tournament "in disgust" at the idea of jousting with a small injured boy, so the Earl vowed that he himself would attack Edmund. But a witch in the crowd named Hannah Cockleford had other ideas. Fed up with the evil Earl, she cast an extremely strong Shield Charm between Edmund and the Earl, who was "squashed flat in his armour" when the Shield Charm knocked him backwards and his horse landed on him. The Earl of Paunchley did not die, but when he came-to he was under the impression that he was a donkey named Hairy Cyril (BoS).
References from the canon
- There are several versions of the incantation. "Protego Totalum" or "protect everything" was used by Hermione to surround their dwelling places with protection while on the run from the Death Eaters (DH14,DH22). "Protego horribilis" loosley translated as "protect from the horrible" casts a protective shield over a wide area, as Flitwick did using a "strong wind" to carry it at the Battle of Hogwarts (DH30).
- Harry learned this spell in his preparations for the third task (GF31).
- Harry used the Shield Charm to defend himself against Snape's Legilimency during Occlumency training and found himself unexpectedly seeing some of Snape's memories (OP26).
- On the first day of DADA in Sixth Year, the class practiced silent Shield Charms. Snape thought Ron was doing a "pathetic" job of his and decided to turn his wand towards Harry as part of the lesson, since Harry had done the spell silently the year before. Harry reacted instinctively by shouting the incantation "Protego" and knocking Snape into a desk (HBP9).
- Harry used this spell to defend himself and to stop various Death Eaters from Summoning the prophecy away from him during the Battle of the Department of Mysteries (OP35, OP36).
- Mentioned as Shield Charm in Ministry leaflet (HBP3).
- According to the twins, many adult wizards as of Harry's sixth year cannot cast this spell properly, hence the popularity of the Weasleys' Wizard Wheezes "Shield" clothing line (HBP6).
- Ron, grasping at straws, speculates that Moody could have used a Shield Charm against the Killing Curse (DH6).
- Cast by Remus Lupin, Nymphadora Tonks, and various other wedding guests after Shacklebolt delivered his warning (DH9).
- Cast by Harry to protect Ron from Hermione (DH19).
- Cast by Hermione at the waterfall (DH25).
- Cast by Snape during his duel with McGonagall (DH30).
- Used by Harry at the beginning of his final duel with Voldemort (DH36).
"protego" L. to defend
In the movie Deathly Hallows: Part 2, Flitwick says "Protego Maxima" or "protect to the maximum" instead of "Protego horribilis" to set a shield around the borders of Hogwarts. Instead of doing the spell alone, he is joined by Poppy Pomfrey, Horace Slughorn, and Molly Weasley (DH/f).