Albus Dumbledore is Hogwarts’ headmaster when Harry first arrives in the Harry Potter book series.
Dumbledore is introduced as the elderly wizard who leads Hogwarts School of Witchcraft and Wizardry during Harry’s first year. He is widely respected for his intelligence, magical ability, and opposition to Lord Voldemort. Before becoming headmaster, he taught Transfiguration at Hogwarts.
Michael Gambon and Richard Harris portrayed Dumbledore in the film adaptations, but the character’s role begins in the books. Dumbledore remains headmaster through much of the series, although he is temporarily removed from the school in Harry Potter and the Order of the Phoenix and later replaced briefly by Severus Snape.
Readers sometimes confuse Dumbledore with Professor McGonagall, who is Hogwarts’ deputy headmistress and Transfiguration teacher for much of the story. Dumbledore’s full name is Albus Percival Wulfric Brian Dumbledore, a detail revealed in the later books.