Even those of us who did not agree with everything she did cannot deny the achievements or the influence of Margaret Thatcher. While there is room to debate whether Caesar, Napoleon, Churchill, or whoever, is the Greatest Man in History, when defined purely in terms of personal accomplishment, it is hard to think of any serious challenger to Margaret Thatcher as the Greatest Woman in History by that definition.

For a commoner from a modest background to become the first ever female Head of Government of a major power would have been triumph enough in itself, but it was what she did with that office that set her apart from every other British politician since Churchill.

For better or for worse, she changed Britain completely – and if there was, as with all politicians, a bit of both, on balance the better far outweighed the worse. When she came to power in 1979, Britain was still generally viewed as Konrad Adenauer’s bankrupt millionaire who had not yet realised that he had lost all his money. By the time she left office in 1990, Britain was again an economic powerhouse, the envy of other nations and even their role model.

She also changed the world. She played a pivotal role, along with Ronald Reagan, Pope John Paul II, and Mikhail Gorbachev in bringing the Cold War to a triumphant and surprisingly peaceful conclusion.

However, her greatest legacy may be the re-establishment of Britain’s enterprise culture. In the 1970s business was actively scorned and persecuted by the British government. It was the grocer’s daughter who showed how abolishing exchange controls, cutting taxes, privatising state assets, and reducing overly politicised unions to their proper role could benefit the economy as a whole. Perhaps she could have gone further in cutting red tape, but what she did was enough to encourage a whole new generation of entrepreneurs, many of them people who would never have dreamt of owning their own business before she came along.

Not only did it become possible for almost anyone to be an entrepreneur – it became positively fashionable. To that extent, all entrepreneurs in Britain today – and in countries influenced by the ‘Thatcherite’ British model – are, like it or not, Margaret Thatcher’s Children.

It is the nature of things that strong, healthy children often clash with their parents, but in the end they are usually grateful to them and for them. That is as good as summary as any of Britain’s complex relationship with the Iron Lady – we have had our differences with her but today, in the end, we are grateful.

The greatest British orchestral composer of the last fifty years was not someone of whom we have never heard, whose state subsidised music is played only by state subsidised musicians in state subsidised venues. He and his music are in fact very well known.

John Barry, who died last month, merits comparison with the great “classical” composers – and was able to combine artistic achievement with huge commercial success.

So why was this outstanding Briton, who was admired all over the world, never given a knighthood by his own country? After all, lots of the obscure state subsidised types were knighted. That is, of course, the point.

Like many of the most talented and successful Britons of his generation, Barry was a tax exile. He was forced to live abroad by British tax rates that were punitive in the most literal sense – they punished achievement.

As a result, instead of receiving a reasonable portion of his considerable earnings at the peak of his career, the British state got nothing from him. Withholding a knighthood was the state’s petty revenge for a situation created by its own short-sightedness.

Eventually, again like many of his contemporaries, he returned to Britain in the 1980s after Margaret Thatcher reduced higher rate tax. It is therefore no surprise that the total paid in taxes by higher rate taxpayers in Britain actually increased as a result of that tax cut.

So Boris Johnson, the Mayor of London, is right to call for similar tax cuts today. He is certainly speaking in the best interests of his own city. London has probably benefitted more than anywhere else from the relatively low tax rates that prevailed from Mrs Thatcher’s time until very recently. Not only did the capital become home to a disproportionate number of the returning exiles; it also attracted a large number of wealthy foreign entrepreneurs. These people have contributed to the local economy, and they have also enhanced London’s social and cultural life. It was after the tax cuts that London regained its Swinging Sixties reputation as one of the most exciting, vibrant, and “happening” places in the world.

Nor is it coincidence that many of the talented people who made the original Swinging London in the Sixties became, like Barry, tax exiles in the Seventies. Those who think them hypocrites for that should ask if the real hypocrites are not those who impose taxes on talent and then wonder where all the talented people have gone.