He would go on to become President of the Board of Trade under Campbell-Bannerman, Chancellor of the Exchequer under Asquith and Prime Minister, 1916–22. He led the Liberal Party from 1926 to 1931, overseeing a short-lived revival in the party’s fortunes. A charismatic and mercurial figure, he led the country to victory in the First World War and helped introduce the ideas of Keynesian economics to British politics – but his rivalry with Asquith split the Liberal Party and contributed to its post-war eclipse by Labour.