Micheal Gambon took over the role from the third movie, Harry Potter and the Prisoner of Azkaban, after Richard Harris' death.
Albus Dumbledore.
He was the headmaster of the School of Magic in the Harry Potter series of books and movies.
Albus Dumbledore did.
Ariana Dumbledore.
Albus Dumbledore is male.
Richard Harris, the actor for Albus Dumbledore in the first and second movies.
In the first and second movie, Richard Harris played Albus Dumbledore. After him, Michael Gambon took on the role of Albus. In the memories of Albus Dumbledore, in the seventh and eighth movies, younger Albus is played by Toby Regbo.
Yes, Albus Dumbledore was a mentor to Harry and could be considered as something of a grandfather figure.
Ariana.
Albus Dumbledore
Albus Dumbledore.
She was Albus Dumbledore's aunt.