Which former British Prime Minister was Edward Heath's Foreign and Commonwealth secretary?

Alexander Frederick Douglas-Home, Baron Home of the Hirsel, (2 July 1903 – 9 October 1995) was a British Conservative politician who served as Prime Minister of the United Kingdom from October 1963 to October 1964. He was the last Prime Minister to hold office while a member of the House of Lords, before renouncing his peerage and taking up a seat in the House of Commons for the remainder of his premiership. His reputation, however, rests more on his two spells as Britain's foreign minister than on his brief premiership.

Heath invited Douglas-Home to join the cabinet, taking charge of Foreign and Commonwealth Affairs. As of 2019, Douglas-Home is the last former premier to have served under a successor. Of Balfour's appointment to Asquith's cabinet in 1916, Lord Rosebery, who had been Prime Minister in 1894–95, said that having an ex-premier in the cabinet was "a fleeting and dangerous luxury". Thorpe writes that Heath's appointment of Douglas-Home "was not a luxury but an essential buttress to his administration".