Warner Bros. bought the film rights to the book in 1999 for a reported £1 million. Production began in the United Kingdom in 2000, with Columbus being chosen to create the film from a short list of directors that included Steven Spielberg and Rob Reiner. J. K. Rowling insisted that the entire cast be British or Irish, in keeping with the cultural integrity of the book. The film was shot at Leavesden Film Studios and historic buildings around the UK.