It was not a reshuffle: not even a reconstruction of the government. It was more like one of Stalin’s purges. But there is a crucial difference. Stalin’s victims were dispatched to the Gulag or the firing squad. Theresa May’s survive, on the back benches. They will owe her as much loyalty as they have received.

Apart from the formidable pressure of events, foreign and domestic, the success of this shuffle depends on three individuals – and on their ability to transform their personalities.

There is no harm in Mrs May being tough. Over the past generation, there have been three instances of a PM failing to control a senior minister. Oddly enough, two of them occurred under Margaret Thatcher: Michael Heseltine over Westland in 1985/86 and Nigel Lawson over monetary policy in 1988/89. The first episode threatened her Premiership; the second gravely weakened it. There followed Tony Blair’s utter, abject and humiliating failure to deal with Gordon Brown throughout the entire ten years of his innings in No.10. He clearly thought that Gordon did have weapons of mass destruction. None of these episodes made for good government. The new Prime Minister would be well advised to study those precedents, and shun them.

But there is a profound difference between toughness and a persecution complex. Mrs May cannot do everything herself. She will have to learn to trust her ministers. Central strategic direction from No.10: essential. Attempts to micro-manage every aspect of policy: futile and fatal.

Assuming that she does want efficiency, she has made life unnecessarily hard for herself by two important appointments: Fiona Hill and Nick Timothy, her new chiefs of staff. Michael Fraser, who eventually became Lord Fraser of Kilmorack, ran the Tory Party’s operations for a generation. He had a famous dictum: the back-room boys should stay in the back room. That is not how Miss Hill and Mr Timothy work. They will see enemies everywhere. When they do not find them, they will create them.

In No.10, crises occur frequently and stress is omni-present. To deal with this, calm is esssential and ill-temper is a confounded nuisance. These two spads threaten to disrupt calm and pile on stress. They are likely to produce a working environment which combines the best aspects of Marcia Falkender and Gordon Brown. By choosing them, Theresa May has opted for fanatical loyalty over good government. She and the government will suffer.

What about Margaret Thatcher? In being an extremely difficult woman, surely la May will merely be following in her example? No: there are profound differences. It is true that Mrs T had a ferocious temper. After she had reduced an early European summit to rubble, Ian Gilmour said: “She will insist on talking to heads of government as if they were members of her Cabinet.”

Yet the Lady also had an overpowering feminine charm; it helped that she was almost exclusively working with males. A tiny number of men she dealt with could withstand her allure; Giscard d’Estaing, Helmut Schmidt, Michael Heseltine, Patrick Mayhew – and there must have been others. But most were mesmerised. Her greatest advisor, Charles Powell, had an instructive nickname for her: La Bionda, a pun on blond and beyond. That captured her personality.

Moreover, however impossible she could often be, those working for her knew that they were helping to reshape their country and make history. So it was worth it. Perhaps now that she is at the top, Theresa May will expand and learn to convey scale and greatness? Or perhaps it will all be about anger, suspcion and insecurity. We shall see. But no-one like Fiona Hill or Nick Timothy would have lasted for five seconds in Margaret Thatcher’s Downing St.

Some commentators have cautiously acclaimed her appointment of Brexiteers in key positions: you Brexit, you fix it. But let us consider the individuals concerned. At Trade, Liam Fox might succeed. Mr Fox is genial and articulate. He should not find it difficult to strike up easy relationships with other trade ministers. If he is then prepared to trust his officials and sherpas to consolidate the detail, that could work.

Apropos of officials, there is now an almost war-time need for rapid improvisation, bringing in dons and businessmen to run new departments, fast. None of that is impossible – until we consider the second character who needs a personality change.

“Easy relationships:” “trust his officials:” the day that becomes true of David Davis, prepare for the Second Coming. Chronically uncollegiate, Mr Davis is a compulsive conspirator. Negotiators must be capable of setting their egos on one side. He has an ego the size of Canary Wharf. In the Brexit negotiations, he faces a task which would daunt a politician of three times his ability, and four times his self-knowledge. He may blunder into error and breakdown.

A conspiracy theory is beginning to circulate, and it runs as follows: the new PM, who does not really want to leave the EU, has appointed David Davis because he will not be able to deliver a deal. Conspiracy theories are rarely plausible. At full stretch, the human mind is barely capable of delivering a decent cock-up. But it is entirely conceivable that Mr Davis will fail.

Finally, the third individual who needs a personality transformation. The world has rarely been more uncertain, more dangerous and more beset by unknown unknowns. Britain is not well-placed to cope with this. In many capitals, there is a feeling that we have parted company with reality: that the UK is no longer a serious country. At this moment, therefore, we do need a serious Foreign Secretary. Mrs May has appointed – Boris Johnson.

Boris is not stupid: far from it. Intellectually, he is as quick over fifty yards as anyone I have ever met. It is the longer distances which become problematic. By one hundred yards, he is at walking pace. There is a real danger that whatever happens to Donald Trump, we will have a Boris Trump at the FCO.

So can Mr Davis stop conspiring? Can Mr Johnson stop clowning? Can Mrs May develop a generosity of spirit and either tame her Spads or sack them? The economy is weaker then it was a month ago, the government is much weaker – and we have just lost a Test Match. The weather apart, there are few grounds for optimism.