The “heavens themselves blaze forth the death of princes”. Among the many weaknesses of the human mind is a tendency to assume that great events must have great causes, and to discount the role of accidents. “For want of a nail the horse was lost” is a far more accurate guide to human events than the scrutiny of heavenly portents. Screw-ups are much more frequent than conspiracies.

Yet some commentators and a few of the simpler-minded Conservative backbenchers in the UK, are agog to believe that degringolade of Liam Fox, who last week resigned as defence secretary, was a Cameronian plot to do down the right of the party. Mr Fox has even been described as the last Thatcherite left standing: romantic Thatcherism’s dead and gone, with O’Foxy to the grave. What nonsense. Mr Fox is no longer in government because he could not tell the difference between a secretary of state and a travel agent. It would be absurd to claim that he is any more Thatcherite than Conservatives such as Michael Gove, George Osborne, Owen Paterson, Iain Duncan Smith or Philip Hammond – or the prime minister, David Cameron. This all raises a question to which there will never be an answer: what is Thatcherism? Is it the Anglo-Irish Agreement, the surrenders of Rhodesia and Hong-Kong, the European Single Act, the deal to maintain the Common Agricultural Policy, the regular increases in government spending? Margaret Thatcher certainly believed in sharing the proceeds of growth.

But Mrs Thatcher was far more than the sum of her actions. She was a demiurge, who saved the UK by reviving the animal spirits of the middle classes: a world-historical figure, who helped Ronald Reagan to win the Cold War, because they both believed that it could be won. She was also a Valkyrie, whose mythic fusion of force and femininity thrilled her supporters. This was the once and future Queen: the Icon of Our Lady of Grantham.