Complex sentence: Hathaway began appearing in commercials at the age three, and later starred in several TV films and TV series such "Battlestar Galactica" at the age six portaying Boxey where he received a nomination in the first Young Artist Awards.
Split into simpler sentences: Hathaway began appearing in commercials at age three, and later starred in several TV films and TV series. At the age of six he starred in "Battlestar Galactica", portaying Boxey, where he received a nomination in the first Young Artist Awards.