A striking, statuesque blonde, Tamsin Egerton got her start early: at the age of seven, she played the key supporting role of Mary in a musical adaptation of the Edwardian-era children's book "The Secret Garden. " By her early teens, Egerton was appearing on British television, playing the young Morgaine in flashback sequences of the television version of Marian Zimmer Bradley's "The Mists of Avalon." Her knack for playing fantasy characters led to the role of Princess Elenora on the children's adventure comedy series "Sir Gadabout: The Worst Knight in the Land." She made her feature film debut in a supporting role in British comedian Rowan Atkinson's 2005 black-humored farce "Keeping Mum." The following year, she co-starred in the family drama "Driving Lessons," in which she played Sarah, the unrequited love of main character Ben (Rupert Grint). In 2007, she played ''posh totty'' schoolgirl Chelsea Parker in a reboot of the "St. Trinian's" series of knockabout comedies set at an over the top private girls' school; she repeated the role in 2009's "St. Trinian's II: The Legend of Fritton's Gold." In 2010, she scored her highest profile film role thus far in her career, co-starring in the heist-driven action film "18.104.22.168" as part of a quartet of beautiful female thieves.