Fearless Anna sets off on an epic journey with rugged mountain man Kristoff to find her sister Elsa, whose icy powers have trapped the kingdom of Arendelle in eternal winter.
The most successful animated movie of all time might not have been a global success had there not been some last-minute changes to the script.
Frozen roped in more than $US1 billion in box office sales for Disney after its release in 2013, catapulting the animated film into the list of the most successful movies ever made. It also snapped up an Oscar for Best Animated Feature film.
Now, Frozen's producer has revealed the film's ending was tweaked in order to make the whole storyline more "satisfying".
Speaking to Entertainment Weekly, Peter Del Vecho said the original script looked very different to the movie millions of people around the world saw in cinemas.
"When we started off, Anna and Elsa were not sisters," he said. "They weren't even royal. So Anna was not a princess. Elsa was a self-proclaimed Snow Queen, but she was a villain and pure evil - much more like the Hans Christian Andersen tale.
"We started out with an evil female villain and an innocent female heroine and the ending involved a big epic battle with snow monsters that Elsa had created as her army."
But Del Vecho said the team went back to the drawing board as they felt this ending "wasn't satisfying".
"The problem was that we felt like we had seen it before," he said. "We had no emotional connection to Elsa - we didn't care about her because she had spent the whole movie being the villain. We weren't drawn in. The characters weren't relatable."
As a result, the writers decided to make Elsa and Anna sisters. And instead of making Elsa a cookie-cutter villain, they painted her as someone who was afraid of her powers because she didn't want to hurt her family.
"Instead of the traditional good versus evil theme, we had one that we felt was more relatable," he said. "The premise of the movie became that love is stronger than fear."
Disney is planning a Frozen sequel, but it won't be released until after 2019.