The history of Britain in the post-war period is undoubtedly a history of decline. In the last fifty years Britain has tried to maintain a leading role in the world, based on its heroic defence of democracy in World War II and its links with the Commonwealth countries, the ex-colonies of the now lost British Empire. Yet a succession of economic crises, the predominance of the USA and its "Cold War" politics, and the Franco-German project of a United Europe have forced Britain to partly abandon its pretences to world leadership. Arguably, Britain now occupies an uncomfortable secondary position among the world's nations, under the powerful shadow of its former colony, the USA, and lacking a firm pro-European stance. Ten Prime Ministers –four Labour, six Conservative– headed the British Government between 1945 and 1990. Labour ruled the country for seventeen years, the Conservatives for twenty-eight, including the eleven years under Margaret Thatcher, the longest-serving Prime Minister of this century (1979-1990). Despite frequent changes of Government, history has run its own course, shaping an economic, social and cultural new order beyond the control of the politics and ideology of either Labour or Conservatives.