The subject of this book is the place of friendship in public life. Some people would say friendship has no real place there at all, and Graham Stewart seems to acknowledge this cynical view by choosing as his epigraph Harry Truman’s maxim, ‘If you want a friend in Washington, buy a dog.’ But there is, as he rightly indicates, more to the matter than that. The paradox is that the life of politics, whether practised in parliaments or courts, naturally encourages alliances that can become close friendships – and then produces the conflicts that destroy them. Destructive influences can arise from a difference over principles (as with Edmund Burke and Charles James Fox on the French Revolution) or rivalry for power and position (Stewart cites the personal antipathy between Tony Blair and Gordon Brown, close allies in reforming the Labour Party who later disagreed over who was to lead it). The termination of a friendship between persons of power can lead to highly emotional drama. There was a famous scene in the House of Commons over the Fox–Burke rupture. Both men were reduced to tears as their twenty-five-year intimacy came to a painful and very public end. Perhaps we should not expect anything at that emotional pitch in these less demonstrative times, but, as the title of the book implies, strong feelings are likely to be aroused.

Such feelings were certainly involved in the various episodes, drawn from several centuries, which are here subjected to detailed and learned scrutiny. The bond between Queen Anne and Sarah, Duchess of Marlborough, for example, involved a mutual passion