Personal rivalry is the very stuff of politics. The causes and controversies, the parties and the technology have changed, but political conflict is still dramatised by the competition of ambitious individuals for the highest offices. Over the past two hundred years, the size of the electorate has grown enormously and the means of reaching it transformed out of all recognition; the chamber of the House of Commons has been usurped as the forum for national debate first by public meetings, press and television and now by the Internet. But human nature does not change. The lure of power still attracts men, and now women, keen to cross swords and bandy arguments, scheme and manoeuvre for advancement, clothing ambition in a cloak of high principle and public service. In almost every period, outstanding champions arise to embody the dominating movements and ideas of the time, defining themselves against each other and shaping the political argument of the day in their own image. Peace or war; protection or free trade; capitalism or socialism - in every case ideology is inextricably entwined with personality. John Campbell's new book finds a fresh angle on these battles by considering eight pairs of rivals and showing how their antagonism, often evolving into outright loathing, has determined the course of political conflict over two centuries. In the eighteenth and nineteenth centuries the greatest duels were between the leaders of opposing parties; in the twentieth they have tended to be fought between members of the same party - though it is worth recalling that both Pitt and Fox and Gladstone and Disraeli started as competitors within the same parties before rivalry drove them apart. In each of his seven case studies - Fox and Pitt, Castlereagh and Canning, Gladstone and Disraeli, Asquith and Lloyd George, Bevan and Gaitskell, Macmillan and Butler, Brown and Blair - Campbell combines a vivid narrative with an authoritative assessment of the historical legacy.