From the official synopsis:
A beautiful, pure-hearted young woman, Maleficent has an idyllic life growing up in a peaceable forest kingdom, until one day when an invading army threatens the harmony of the land. Maleficent rises to be the land's fiercest protector, but she ultimately suffers a ruthless betrayal - an act that begins to turn her pure heart to stone. Bent on revenge, Maleficent faces an epic battle with the invading king's successor and, as a result, places a curse upon his newborn infant Aurora (Elle Fanning).
Also starring Sharlto Copley, Miranda Richardson, Brenton Thwaites, Juno Temple, Sam Riley, and Imelda Staunton, the film is scheduled to open wide May 30th, 2014.