Although his parents made their living in showbiz, his director father and screenwriter mother were cautious when a young Gyllenhaal expressed an interest in acting, forbidding him to take a role in 1992's The Mighty Ducks because it required a long location shoot. Still, the budding thespian played a handful of small roles, sometimes in his parents' projects, before making his leading-man debut in the 1999 family drama October Sky. His breakthrough year was 2001, however, with standout turns in a pair of indie films: a haunted adolescent in the cult classic Donnie Darko and a gawky teen in love with an older woman in Lovely & Amazing, a performance he more or less repeated the next year opposite Jennifer Aniston in The Good Girl. With his brooding intensity and penchant for offbeat characterizations, he quickly established himself as a first-rate actor. Even his starring role in the bloated 2004 action blockbuster The Day After Tomorrow and a two-year, high-profile romance with starlet Kirsten Dunst couldn't tarnish his serious image. In 2005 he continued his streak of thoughtful performances and earned his first Oscar nomination as a gay cowboy in Brokeback Mountain. He followed that sterling, BAFTA-winning performance with turns in Zodiac (2007), Brothers (2009) and Prince of Persia: The Sands of Time (2010). The actor, who also had a two-year romance with actress Reese Witherspoon that ended in 2009, is politically active away from the silver screen, supporting progressive causes, Rock the Vote, the American Civil Liberties Union and environmental initiatives.