Complex sentence: In he had a small role, portraying Governor Tarkin in a young age, later known as Grand Moff Tarkin due to his similarity to Peter Cushing who portrayed the same character 20 years ago, in A New Hope.
Split into simpler sentences: In he had a small role, portraying Governor Tarkin in a young age, due to his similarity to Peter Cushing. Cushing portrayed the same character 20 years ago, in A New Hope.