Starting out as a mid-price catalogue reissue specialist, with labels including The Collector Series and Dojo, Castle grew into the largest European owner of repertoire outside the major record companies. It purchased a number of record catalogues, including Pye, Piccadilly, Bradley's, Bronze, Black Sabbath, Sugar Hill, Transatlantic, Beserkley, All Platinum and Solar. They possessed most of the Transatlantic and Trailer catalogue.