Archibald Simpson returned to Aberdeen in 1813, establishing a business competing with Smith. Both firms were successful despite uncertainties due to the War and their careers were described by Miller as "destined to run remarkably parallel". Although at times rivals, Smith often collaborated with Simpson and between these two men their buildings became the nucleus of establishing the style of the heart of the Aberdeen city centre. As the buildings were constructed from silver granite, the city gained the name of the Silver City or alternatively the Granite City.