Great Offices of State have come close to achieving this distinction: Herbert Henry Asquith and Winston Churchill both served as Chancellor, Prime Minister and Home Secretary while Harold Macmillan and John Major served as Prime Minister, Chancellor and Foreign Secretary. Rab Butler and Sir John Simon served as Chancellor of the Exchequer, Foreign Secretary and Home Secretary. Two of the Great Offices of State have often been held simultaneously by one person, most recently by Ramsay MacDonald, Prime Minister and Foreign Secretary in 1924; Arthur Wellesley, the Duke of Wellington, is the only person to have held three of the Great Offices simultaneously, serving
Prime minister of the President of the Executive Yuan. The United Kingdom's constitution, being uncodified and largely unwritten, makes no mention of a prime minister. Though it had "de facto" existed for centuries, its first mention in official state documents did not occur until the first decade of the twentieth century. Accordingly, it is often said "not to exist", indeed there are several instances of parliament declaring this to be the case. The prime minister sits in the cabinet solely by virtue of occupying another office, either First Lord of the Treasury (office in commission), or more rarely Chancellor of the Exchequer