Who played the role of Marcus Aurelius in Gladiator 2000 and Albus Dumbledore Harry Potter?

That's a bit of a trick question! Two different actors played those roles:

* Marcus Aurelius in Gladiator (2000): Richard Harris

* Albus Dumbledore in Harry Potter: Richard Harris played Dumbledore in the first two Harry Potter films (2001 and 2002).

While the same actor played both roles, he sadly passed away in 2002. Michael Gambon took over the role of Dumbledore for the remaining Harry Potter films.