That was over 41 years ago in 1981.
Today she is 76, and has starred in 115 movies in total, 89 since Excalibur was released.
In Excalibur, I think Helen Mirren looks:
Excalibur scores 7.1 out of 10 on The Movie Database.
Helen Mirren's first acting role was as 'Advert Woman' in Herostratus, released in 1967 when she was 21.