Who composed the piano piece Dawn played in Pride and Prejudice?

In the 2005 film adaptation of "Pride and Prejudice," the piano piece played by Keira Knightley's character, Elizabeth Bennet, is "Lady Catherine de Bourgh's Theme," composed by Dario Marianelli. The soundtrack features a blend of original compositions and classical pieces, contributing to the film's romantic atmosphere. Marianelli's work effectively captures the emotions and themes of Jane Austen's novel.