It is not known precisely who created the Disarming Charm. Some wizarding historians claim that it may have been invented by Merlin himself, others claim that its first widespread use was in Madagascar in the 11th century. Even if any of this is true, the fact remains that it was not very popular until 1379, when Elizabeth Smudgling — the most likely inventor, in the opinion of Miranda Goshawk — used it in a duelling contest in Dartmoor. It became Harry Potter's signature spell, and it notably caused the death of Lord Voldemort during the Battle of Hogwarts by rebounding his Killing Curse.