At the young age of eleven, Harry Potter was pulled into a world of magic and informed of his destiny: squaring off against the Dark Lord, Voldemort. Luckily for Harry, he has the help of the best that Hogwarts School of Witchcraft and Wizardry has to offer. Between the Triwizard Tournament, the Ministry of Magic, and the infamous Death Eaters, there are quite a few powerful witches and wizards seen throughout the series.
Source:https://www.cbr.com/harry-potter-strongest-witches-wizards/