Marlon Brando was 69 in Don Juan DeMarco when he played the character 'Dr. Jack Mickler'.
That was over 30 years ago in 1994.
In 2004 he died aged 80, starring in 97 films in his career, 49 of those after Don Juan DeMarco was first released. If he were alive today he would be 100.
In Don Juan DeMarco, I think Marlon Brando looks: