<page_title> List of Prime Ministers of the United Kingdom by age </page_title> <section_title> List of prime ministers </section_title> <table> <cell> Harold Macmillan <col_header> Prime Minister </col_header> </cell> <cell> 92 years, 322 days (33,924 days) <col_header> Lifespan </col_header> </cell> </table>
Harold Macmillan was the one of the longest-lived prime minister in British history.