An improv-trained actress, Allison Williams made her mark as one of the core ensemble members of Lena Dunham's highly acclaimed series "Girls" (HBO, 2012- ). The daughter of "NBC Nightly News" (1970- ) anchor Brian Williams, Williams graduated from Yale, where she was a member of the improv troupe Just Add Water for four years. Although she had made two guest appearances on "American Dreams" (NBC, 2002-05) in 2004 and one on "The League" (FX, 2009- ) in 2011, Williams achieved wider success with a string of viral Internet videos, including writing a series of Funny or Die sketches that featured her as royal newlywed Kate Middleton. On the strength of her improv chops, Williams was tapped to audition for the Lena Dunham/Judd Apatow series "Girls" (HBO, 2012- ) and landed the role of Marnie Michaels, roommate and best friend to Hannah Horvath (Dunham), whose composed, polished exterior hides deep-seated insecurities. In December 2014, Williams starred in the title role of "Peter Pan Live!" (NBC 2014), a live TV adaptation of the beloved musical version of the J.M. Barrie tale.