Jake Gyllenhaal was born on Dec. 19, 1980 to children’s television producer-turned-screenwriter Naomi Foner (“Running on Empty,” 1988; “Losing Isaiah,” 1995), and published poet and film director Stephen Gyllenhaal (“Losing Isaiah,” 1995; “Homegrown,” 1998). Gyllenhaal and older sister Maggie grew up in Los Angeles and thrived in the intellectual, arts-oriented environment their parents created. He was acting by age 11, appearing on the big screen in a brief turn as Mitch’s (Billy Crystal) son in "City Slickers” (1991) and in the little-seen kid's adventure "Josh and S.A.M." (1993), as a mean step-brother to the title characters. The 1993 film "A Dangerous Woman," penned by mom and directed by dad, turned into a family affair, with the casting of brother and sister in supporting roles. As a teenager, Gyllenhaal attended the prestigious Harvard-Westlake private school in Los Angeles, but his parents were determined to keep their Hollywood kids firmly grounded, mandating they take on normal summer jobs and celebrating Gyllenhaal’s bar mitzvah with a day of service at a homeless shelter. Gyllenhaal augmented his paychecks as lifeguard and busboy with occasional TV appearances, including a 1994 episode of “Homicide: Life on the Street” (NBC, 1993-99) and by gigging around Hollywood as a singer with a band called Holeshot.

In 1998, Gyllenhaal appeared as a hippie son in the indie pot comedy, “Homegrown,” but gave a truly break-out leading performance in the feel-good favorite "October Sky,” based on the real life story of NASA engineer Homer Hickam Jr. Compelling and sincere without teetering into sentimentality, Gyllenhaal announced his arrival as a bright new talent by playing Hickam, a boy interested in rocket science whose brilliant mind and staunch dedication wrote him a ticket out of a dead-end mining town. Following high school graduation later that year, Gyllenhaal began attending Columbia University in New York, where his mother had received a Master’s Degree and his sister was enrolled. The spiritually-minded actor worked towards a degree in Eastern Religions and also concentrated on literature and poetry classes, but after a few years, he felt the pull to resume his promising film career.

He got the chance to solidify his status as an indie film actor with great depths in the Sundance-screened "Donnie Darko" (2001). Gyllenhaal was crucial to the artistic success of the indescribably odd time travel/psychological thriller about a high school teen haunted by garish nightmares and premonitions of the end of the world. He was nominated for an Independent Spirit Award for his lead, even though the film predictably sank quickly at the box office, rising in cult status only after its DVD release and addition to the midnight movie art house scene.

Gyllenhaal’s next outing, the drama "Highway," with Jared Leto and Selma Blair, came and went without much notice, while the offbeat comedy "Bubble Boy" (2001) was widely criticized. The missteps were hardly enough to ward off independent directors, and Gyllenhaal followed up with a strong supporting performance in Nicole Holofcener’s “Lovely and Amazing” (2001) before co-starring opposite Jennifer Aniston in Miguel Arteta’s "The Good Girl" (2002), a modern take on “Madame Bovary,” in which Gyllenhaal played the bookish, intriguing love interest of a bored cashier.

"Moonlight Mile" (2002) marked a career highpoint for the young actor, who shared the screen with such heavy-hitting thespians as Dustin Hoffman, Holly Hunter and Susan Sarandon, in the role of a young man whose fiancé is accidentally killed and unexpectedly spends a great deal of time grieving with her family. The film was based on the screenwriter’s experiences dealing with the murder of the actress Rebecca Schaeffer, who was killed by a fan. Following the encouragement of Hoffman, Gyllenhaal expanded into the theater, debuting on London’s West End in 2002 in the Kenneth Lonergan play, This is Our Youth,” about a group of privileged, aimless teenagers in the 1980s. He received an Evening Standard Theatre Award in the category of "Outstanding Newcomer" for his performance. Returning to the big screen, Gyllenhaal opted for an atypical big-budget summer outing — director Roland Emmerich's "The Day After Tomorrow" (2004), in which he played the son of a climatologist (Dennis Quaid) trapped in New York City as a new ice age descends on the planet.

That election year, Gyllenhaal bared his political side by campaigning on behalf of John Kerry and encouraging young adults to turn up at the polls in a PSA for “ock the Vote.” His other social activism included work with the American Civil Liberties Union and various environmental initiatives. But in 2005 – the most prolific of Gyllenhaal’s career – his name suddenly carried a whole lot more clout, as the young actor rose from art house favorite to one of the most respected young actors in Hollywood. In "Proof," director John Madden's adaptation of David Auburn's Pulitzer Prize- winning play, he played a self-effacing math student who idolizes his brilliant but schizophrenic teacher (Anthony Hopkins) and forms a tenuous bond with his troubled daughter (Gwyneth Paltrow). The film featured Gyllenhaal's most mature work to date, and positioned him well for future roles as a romantic leading man who could hold his own among acting heavyweights.

If "Proof" was confirmation of his talent, his next feature that year was a revelation: "Jarhead" (2005) was director Sam Mendes' insightful, psychological adaptation of Anthony Swofford's bestselling memoir of his service during the 1990 Gulf War in Iraq. Gyllenhaal turned in a startlingly deep and effective portrayal of Swofford, a naive, callow youth who enlists in the Marine Corps and is highly trained to be a sniper, but finds himself mired in paranoia, boredom and existential angst while stationed in Iraq, but not allowed to use his skills as nations stood on the brink of war. The role was “life changing” for Gyllenhaal, who was cast in an entirely new light and took his performance to dark, probing places, appearing to mature onscreen as the film unfolded.

But the film that made Gyllenhaal a household name was director Ang Lee's haunting and heartbreaking drama "Brokeback Mountain" (2005), an adaptation of the short story by E. Annie Proulx. In one of the most talked about films of the year, Gyllenhall played Jack Twist, a ranch hand who has a homosexual relationship with a fellow closeted ranch hand (Heath Ledger) during a remote sheep drive, and revisits the agonizing romance sporadically over several decades. The role showcased Gyllenhaal’s combination of masculinity and soulfulness to its finest, earning a Supporting Actor Oscar nomination and winning a BAFTA for his accomplishment. During shooting Gyllenhaal became close friends with co-stars Ledger and Michelle Williams and was named the godfather of the pair’s daughter, Matilda.

He followed up with a starring role in “Zodiac” (2007), David Fincher’s take on the famed Zodiac Killer, as a cartoonist at The San Francisco Chronicle during the 1970s murders, who got involved in the case and later became the foremost expert on the elusive killer who reveled in taunting the media and police. Gyllenhaal rounded out the year with “Rendition,” Gavin Hood’s ambitious tale of a CIA agent investigating the government’s interrogation practices of suspected terrorists. The film was released around the same time as several others that sought to examine international policies of the era, but “Rendition” ranked among the least popular of a generally unpopular genre and was criticized for oversimplifying its complex subject matter. Gyllenhaal earned more press for his relationship with co-star Reese Witherspoon, on the rebound after a split from husband Ryan Phillippe. In 2008, he was slated to appear in another politically-tinged drama, an adaptation of Danish filmmaker Susanne Bier’s “Brothers” about a family’s changing dynamics when one brother is sent to war in Afghanistan. But first – on Jan. 22, 2008 – he was forced to deal with the accidental prescription drug overdose of his “Brokeback Mountain” co-star, Heath Ledger, which, by all accounts, devastated him. He was, after all, the godfather of both Ledger’s and Michelle Williams’ daughter, Matilda.