<page_title> List of current state leaders by date of assumption of office </page_title> <section_title> Prior to 1970 </section_title> <table> <cell> 6 February 1952 <col_header> Assumed Office </col_header> </cell> <cell> Elizabeth II <col_header> Leader </col_header> </cell> <cell> United Kingdom <col_header> Assumed Office </col_header> </cell> <cell> Queen <col_header> Leader </col_header> </cell> </table>
The current monarch of the United Kingdom is Queen Elizabeth II, who has reigned since 1952, making her the longest-serving current head of state.