I Capture the Castle is author Dodie Smith's first novel. Published shortly after World War II in 1948 (the book was written while Smith and her husband were in California during the war), I Capture the Castle follows a young 17-year-old girl named Cassandra Mortmain. She is incredibly bright and keeps daily journals during which she ruminates on what is occurring in her life, her poverty-stricken, and the places around her. The story is told through Cassandra's journal. Above all, though, I Capture the Castle is a coming-of-age story in which our narrator Cassandra transforms from a little girl at the beginning of the book into a young adult towards the end. The novel ruminates on issues of poverty, getting older, money, religion, and romance.
Upon release, I Capture the Castle was widely read and very well-received. In 2003, for example, the book was listed as the 82nd-best book in the BBC's "The Big Read" survey. Sally Engelfried of Common Sense Media liked the book, writing that "Cassie's engaging voice in I Capture the Castle has a surprisingly contemporary feel for a novel written more than 60 years ago."
In 1954, Smith adapted the novel into a two-act play "with musical notes" of the same name. The book was adapted into a film in 2003. It was directed by Tim Fywell and starred Romola Sadie Garai as Cassandra and received surprisingly positive reviews. Among those who loved the film included the late film critic Roger Ebert, who awarded the film 3.5 out of 4 stars and called both the book and the film "dreamy." In 2015, the book was adapted by BBC Radio 4 and Nadia Molinari into a radio play.