premise: Tilda Swinton is an actress.
hypothesis: Katherine Matilda `` Tilda '' Swinton ( born 5 November 1960 ) is a British actress , performance artist , model , and fashion muse , known for her roles in independent and Hollywood films . Swinton won the Volpi Cup for Best Actress at the Venice Film Festival for her performance as Isabella of France in Edward II ( 1991 ) . She then starred in the crime drama Julia ( 2008 ) , I Am Love ( 2009 ) , and the psychological thriller We Need to Talk About Kevin ( 2011 ) . She is also known for her performances as the White Witch in the Chronicles of Narnia series ( 2005 -- 10 ) . Swinton won the Academy Award for Best Supporting Actress and the BAFTA Award for Best Actress in a Supporting Role for her performance as lawyer Karen Crowder in Michael Clayton ( 2007 ) .