For someone who regards himself as a disruptive outsider, Dominic Cummings has never felt the need to please anyone. And so Boris Johnson had his work cut out when he asked Cummings to join him in Downing Street last July. The new prime minister described it as a “hairy” mission.

One friend recalls: “Boris was really turning the thumbscrews on Dom saying, ‘You’ve got to come in, you’ve got to come in.’”

Cummings tabled what he called a series of “terrorist demands” to the incoming prime minister after judging, according to one friend, that his team had monumentally failed to draw up a coherent plan.

The boldest demand, which was at the centre of the eventual showdown with Sajid Javid, was to be given control of the network of special advisers, the political appointees who work for cabinet ministers. By controlling the special advisers Cummings would gain significant leverage over cabinet ministers.

To his surprise, the new prime minister said yes to his demands. Cummings therefore entered Downing Street with one immediate plan - to sort out the “mess” of Brexit - and a longer vision to transform the workings of government.

“We are going to bulldoze our way to make sure Brexit happens,” was the Cummings view at the time. “It has to happen.”

In a fraught autumn for the Tory party, which saw the evisceration of the pro-European wing of the party, Cummings deployed his own powers, sometimes without mercy.

Relations started to sour with Javid when his special adviser Sonia Khan was unceremoniously and highly controversially marched out of No 10 last August after falling out with Cummings. The sacking of Khan - who was escorted out of Downing Street by an armed police officer - chilled the atmosphere in Whitehall. Javid was not even aware it was happening.

Cummings is not the loner he is sometimes portrayed as, and knows power when he sees it. On the day Johnson became prime minister, a scruffy-looking Cummings made sure to frame himself in the corner of a photo taken as the cabinet secretary and the man in charge of the civil service, Sir Mark Sedwill, welcomed the new PM to No 10. Sedwill could well be seen as the epitome of the sort of generalist - a career flitting between the Foreign Office and the Home Office - scorned by Cummings.

But Gisela Stuart, the former Labour minister who chaired the Vote Leave campaign, who knows both men well, says: “I remember looking at that picture and I thought Sedwill and Dom have a lot in common. Both of them are big picture people, both of them are deeply strategic, both of them are terribly focused. I think they want the same thing.”

With the fate of Brexit unknown in a hung parliament, Cummings advised Johnson to take a risky gamble by going for an early general election.

Cummings is widely praised for pushing for it but was blunt about the dangers at the time. “This election is very risky, very risky for us,” he was heard to say. “Anyone who says they know what is going to happen or thinks we will walk it is an idiot.”

The electoral gamble paid off. But Cummings was unhappy – feeling that his control of special advisers had failed to impose enough discipline. He was highly suspicious of the team working for Javid. Cummings had technically taken control of the network of special advisers but they were still in effect answerable to their cabinet minister and not to him.

Also, Cummings wanted to inject new characters into the machinery of government. He used a blog on 2 January to call on “weirdos and misfits with odd skills” to join him in delivering the large changes in policy and decision-making he said were required by Brexit.

Cummings indicated that 35,000 people had answered his call. They must have been attracted by the job specification in which he wrote: “I don’t want confident public school bluffers. I want people who are much brighter than me who can work in an extreme environment. If you play office politics, you will be discovered and immediately binned.”

But Cummings faced a rebuke from a writer cited in one of his blogs. William Gibson mocked Cummings for appearing to liken himself to the “quasi evil genius” Hubertus Bigend in his novel Pattern Recognition. “The idea of people like that being made bureaucrats is quite unnerving,” Gibson told the BBC.

A former cabinet minister accuses Cummings of ruthless tactics which have involved injecting populism into the political discourse and undermining the constitution when parliament was suspended last year. David Gauke, who stood unsuccessfully as an independent candidate in the election after he was deprived of the Tory whip, says: “You can admire the ruthless determination to pursue a strategy which very few people would do in as determined a manner as he has done. But it is a strategy which is reckless and damaging for the country in the undermining of institutions.”

But the former MP Sir Nicholas Soames, who lost the Tory whip at the same time as Gauke, admires Cummings. Soames, who eventually had the whip restored, says: “Dominic Cummings is an exceptionally gifted and clever man. Every government needs a disruptor. Governments that don’t have disruptors become complacent and run out of steam. The predictable pretend loathing of Cummings is totally pathetic.”

But Cummings has made enemies in a potentially significant camp - friends of Sajid Javid. “The handling of Sajid was gratuitous,” one said. “Is it really wise to create a prince across the water so early on?”

Friends of Cummings are divided on what the future holds for him as he lives with the inevitable compromises of government. One says he is a pragmatist.

But another says that Cummings’s irritation with David Cameron’s vetoing of his plan to scrap GCSEs shows he is prepared to walk. “Dom is not there to please. He’s there to get stuff done. If the principal, Boris, doesn’t follow that plan he will say: ‘You’re not interested in taking my advice, I’m out of here.’”

A divisive polemicist, both charming and abrasive, Dominic Cummings is wielding immense power in the name of a prime minister with an historic mandate. It is a natural meeting of minds between two idiosyncratic political beasts with eclectic interests in the classical world and beyond.

Johnson summoned Cummings in his first hour of need when Brexit and the future of the Conservative party were in jeopardy. Cummings was the right fit for the first phase of Boris Johnson in No 10. It will be a cliffhanger to see how long the match lasts.