Albus Dumbledore

Albus Dumbledore was the Headmaster of Hogwarts School of Witchcraft and Wizardry. Considered by many to be the most powerful wizard of his time, he was many times offered the post of Minister of Magic but refused to leave Hogwarts.

Before becoming Headmaster, Dumbledore taught Transfiguration for many years, teaching such students as Tom Riddle and Rubeus Hagrid.