Born in West Berlin, Germany, Monaghan was raised by his father, Austin, a school teacher, and his mother, Maureen, a nurse; both of whom were British expatriates. After his family moved to Stockport, England when he was 11 years old, he attended St. Anne's RC High School, while performing in school productions of "A Christmas Carol" and "Oliver Twist." Soon after, Monaghan joined the Manchester Youth Theatre, which spurred the interest of an agent, who landed him a series of television auditions. He briefly went to Aquinas College to study drama and English literature before branching off as a professional actor when he scored the role of Geoffrey Shawcross, the youthful sidekick of an amateur sleuth (Patricia Routledge) on the quirky comedy-drama, "Hetty Wainthropp Investigates" (BBC1, 1996-98). Monaghan went on to additional stage work, as well as the BBC radio sitcom "Stockport So Good They Named It Once," on which he supplied the voice of a sharp-witted teenager. But at the time, he longed to make a film.Monaghan soon had his wish fulfilled when he played a small role in the Cold War drama "Hostile Waters" (HBO, 1997), which was soon followed by "Monsignor Renard" (PBS, 2000), a four-part British-made miniseries about an occupied French village during World War II. But before he went to that project's shoot in France, Monaghan recorded a video audition for what would become his first full-fledged feature film, "Lord of the Rings: The Fellowship of the Rings" (2001). The video audition had been for the central role of Frodo Baggins in director Peter Jackson's ambitious production of J.R.R. Tolkien's fantasy classic. But Jackson and his producers had yet to find the right Meriadoc "Merry" Brandybuck, friend of Frodo who helps undertake his quest to cast the One Ring into the fires of Mount Doom before Sauron's forces of evil destroy Gondor. Monaghan was chosen play Merry and he went to New Zealand, where he spent the better part of two years filming all three movies in succession, which included the second and third installments, "The Lord of the Rings: The Two Towers" (2002) and "The Lord of the Rings: The Return of the King" (2003). In the first film, Monaghan played the chubby hobbit in a foam fat suit, a stifling condition that forced him to drink voluminous water to remain hydrated. But the rigors of the quest, which transformed him from comic relief to warrior, honed him down to his regular size by the final film. Meanwhile, he became good friends with Billy Boyd, who played Merry's cousin and closest friend, Pippin, the second hobbit stowaway on the ring quest. After the trilogy wrapped, Monaghan returned to Manchester, but soon moved to Los Angeles after feeling like a fish out of water and wanting to be where the Hollywood action was. Still, his only job offers were for more "fantasy/pixie/goblin kind of parts," which he turned down in an effort to avoid typecasting. He fell into a funk, smoking pot and drinking daily, until he got back in contact with Boyd, who advised him to start doing something he enjoyed. He embarked on a healthier regimen while taking a succession of supporting roles in indie films, playing a petty, weed-addled criminal in the U.K.-set "Spivs" (2004), which he followed with a much-maligned martial arts action flick, "The Purifiers" (2004), and a tale of a pathos-ridden leader of a rock band, "Shooting Livien" (2005). Though he was fulfilling his dreams of making movies, Monaghan would soon become a star thanks to the small screen. In early 2004, he landed the role of Charlie Pace, a washed-up, heroin-addicted former rock star who crash lands with 47 other survivors on a remote and rather strange island on the hit series, "Lost" (ABC, 2004-2010). Stranded on the uncharted island that contains an untold amount of mysteries to be unraveled, the survivors struggle to find out why they were brought to the island in the first place, while at the same time battling a violent group of mysterious Others. Monaghan's Charlie detoxifies from his heroin addiction with the help of the faith-based John Locke (Terry O'Quinn), while he faces the dark vestiges of his past and finds a place in the makeshift society, soon making him one of the more popular characters in the show's large cast. "Lost" became a surprise hit, ranking No. 14 in the network ratings for the season, winning the Outstanding Drama Emmy the next year, developing a fanatical cult following and spawning a raft of ancillary media and products, including action figures, comic books, novels, video games and countless websites dedicated to deciphering the most innocuous clues that might help unveil the larger mystery.Things picked up for Monaghan personally as well, as he began a long-term relationship with co-star Evangeline Lilly, who played outlaw Kate Austen. Meanwhile, Abrams and fellow exec producer Damon Lindelof famously declared that as long as Monaghan came to the set, Charlie would not die - in reference to the show's penchant for killing off characters. But Abrams' success saw him hatch new projects, leaving the show's helm to Lindelof and Carlton Cuse, who began reconsidering Charlie's immortality. Though they kept scripts close to the vest, rumors of Charlie's demise hit the Internet months in advance, prompting a internet-rooted movement to "Save Charlie." But indeed, in the season three finale, Charlie took his final step in his heroic journey and sacrificed himself to save fellow survivors. Reports varied as to Monaghan's sentiments about the development, some saying it irked him, while others stating that he had grown unhappy with his screen time. Monaghan himself said that he wanted to avoid being known solely as a single character. He did, however, return in cameo fashion over the next couple of seasons, including during the final season that aired in 2010. Though "Lost" managed to eat up most of his time, Monaghan did manage to venture out once his time on the show was over. After an episode of "Chuck" (NBC, 2007-12), he had a prominent role in the B-horror flick, "I Sell the Dead" (2008), an irreverent, well-received black comedy that cast him as a devil-may-care 18th century grave-robber who gets caught up in supernatural doings. In May 2009, he joined a cast of top-line actors playing the superpowered denizens of the fourth film in the X-Men franchise, "X-Men Origins: Wolverine" (2009). Monaghan, originally slated to play the oddball bird-powered mutant Beak, was revamped mid-production as the electricity-channeling Bolt. Following the low-budget horror flick "I Sell the Dead" (2009), Monaghan returned to the small screen with a starring role in the hit sci-fi drama, "Flash Forward" (2009-10). Based on Robert J. Sawyer's 1999 science fiction novel of the same name, the series followed the story of Special Agent Mark Benford (Joseph Fiennes), an FBI agent determined to find out the cause of a two-minute, worldwide blackout and "flash-forward," in which people appear to see a vision of their lives six months into the future. Monaghan played Dr. Simon Campos, a quantum physicist who denies his responsibility for the blackout while battling with the knowledge that his flash-forward involves killing a man.