 Rees-Mogg is the grandson of Thomas Richard Morris, a former mayor of St Pancras, and the uncle of Olympic athlete Lawrence Clarke.In 2006 Rees-Mogg became engaged to Helena Anne Beatrix Wentworth Fitzwilliam de Chair, a writer for a trade magazine and the only child of Somerset de Chair and his fourth wife Lady Juliet Tadgell.Rees-Mogg had first met de Chair, a close friend of his sister, when they were children, and they began dating the year before their engagement, after Rees-Mogg had gained the blessing of Lady Juliet.