Formed out of a breakaway from the mainstream Liberal party in 1931, the Liberal National party (renamed the ‘National Liberal Party’ in 1948) preserved a separate identity for almost 40 years. During this time they helped ensure that the Liberals themselves would not return to their former status of a governing party while helping to broaden the electoral appeal of their Conservative allies, contributing significantly to the Tory domination of the British political scene in the middle of the twentieth century. Here, David Dutton shows us for the first time how the National Liberals were a potent force in shaping the evolution of British politics in the middle decades of the twentieth century, before they finally merged with the Conservative party in 1968.