<P> Created by directors Chris Buck and Jennifer Lee, Elsa is loosely based on the title character of "The Snow Queen", a Danish fairytale by Hans Christian Andersen . In the Disney film adaptation, she is introduced as the princess of the fictional Scandinavian kingdom of Arendelle, heiress to the throne and the elder sister of Princess Anna (Kristen Bell). Elsa has the magical ability to create and manipulate ice and snow . She inadvertently sends Arendelle into an eternal winter on the evening of her coronation . Throughout the film, she struggles first with controlling and concealing her abilities and then with liberating herself from her fears of unintentionally harming others, especially her younger sister . </P> <P> The Snow Queen character, neutral but cold - hearted in the original fairytale and villain in numerous adaptations of the character, proved difficult to adapt to film due to her transparent depiction . Several film executives, including Walt Disney, attempted to build on the character, and a number of scheduled film adaptions were shelved when they could not work out the character . Buck and his co-director, Jennifer Lee, were ultimately able to solve the dilemma by depicting Elsa and Anna as sisters . As much as Anna's struggle is external, Elsa's is internal . This led to Elsa being gradually rewritten as a sympathetic, misunderstood character . </P> <P> Elsa has received largely positive reception from reviewers, who praised her complex characterization and vulnerability . Menzel was also widely praised for her vocal performance of Elsa, especially that of her performance of the song "Let It Go", with critics frequently calling her a "powerhouse". </P> <P> Attempts were made as early as 1937 by Walt Disney to adapt Hans Christian Andersen's fairy tale, "The Snow Queen", into a film . The tale focuses on two children, one named Gerda, who served as the basis for Princess Anna, and the other named Kai, who is "cursed with negativity" after his heart is pierced with a shard of glass from an enchanted mirror and is later kidnapped by the Snow Queen . However, Disney struggled with creating a believable, multi-dimensional adaption of the fairy tale's title character, who was intended to be a villain . In the story, she is described as "a woman, dressed in garments of white gauze, which looked like millions of starry snow - flakes linked together . She was fair and beautiful, but made of ice--shining and glittering ice . Still she was alive and her eyes sparkled like bright stars, but there was neither peace nor rest in their glance ." Disney was unable to find a way to make the Snow Queen more real and eventually abandoned film plans . </P>

Who played the characters in the movie frozen