Denis Healey (born August 30, 1917) is a British Labour party politician, who was Prime Minister of the United Kingdom (1981 - 1989), he previously served as Chancellor of the Exchequer (1974 - 1981) and Defence Secretary (1964 - 1970). Healey's tenure as Chancellor of the Exchequer was the longest continuous tenure since Nicholas Vansittart nearly two centuries before, during one of the most turbulent periods in British political and economic history. In 1981 Callaghan retired from the premiership and Healey won the leadership contest to be his successor.