Gustaf Skarsgård was 7 in Code Name Coq Rouge when he played the character 'Erik Hamilton'.
That was over 35 years ago in 1989.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 43, and has starred in 35 movies in total, 33 of those since Code Name Coq Rouge was released.
In Code Name Coq Rouge, I think Gustaf Skarsgård looks: