The prime minister ousted a number of high profile names while Sajid Javid was pushed into quitting as Chancellor in an acrimonious spat over special advisers .
Andrea Leadsom, Esther McVey, Theresa Villiers, Geoffrey Cox and Julian Smith were the most notable figures to be ousted.
Dominic Cummings, Mr Johnson's chief special adviser, is thought to have had a major sway in the Cabinet changes having previously hit out at its former composition.
As the newly picked team gathered, the PM kept the date of the Budget and the fate of the Treasury’s fiscal rules open.
“We’re here to deliver for the people of this country,” the Prime Minister told the gathering at No 10 — before showing off his tighter grip by leading ministers in chants of the manifesto headlines about more police and hospitals.
Addressing the room, Mr Johnson said: “Welcome to today’s new Cabinet. This will be the Cabinet of delivery.”
Detailing his goals, he said: "We must get on with our basic work. We know what it is, we're going to cut crime, we're going to tackle homelessness and we're going to tackle waiting lists in our NHS."
He went on to ask those in attendance to say together numbers of hospitals planned for construction, nurses to be recruited and police officers to be hired.
Ending his opening address to the ensemble, he said now was the time to "put the pedal to the metal".
Behind the scenes, Mr Cummings was assembling new teams of special advisers including a temporary team to work with new Chancellor Rishi Sunak.
Officials said there was no clarification yet over whether the Budget would be delivered as scheduled on March 11.
However, there were attempts to calm speculation that the fiscal rules announced by ex-Chancellor Mr Javid during the election campaign would be watered down to permit a spending boom on borrowing.
“The manifesto applies,” said one.
The resignation of Mr Javid was a bombshell during yesterday’s reshuffle. More details emerged today of how Mr Johnson tried to persuade him to stay, including during a 10-minute one-to-one meeting. However, Mr Javid refused to sign up to conditions including that he would sack his team of advisers.
There were a number of promotions and shifts to coincide with the sackings.
Alok Sharma was promoted from international development to become the new business secretary.
He will also be minister for the COP26 UN climate summit, which is due to take place in Glasgow in November.
Anne-Marie Trevelyan joined the Cabinet as international development secretary, following serving as a defence minister.
Oliver Dowden became a full Cabinet member as culture secretary, while George Eustice was promoted to Environment Secretary from his previous role in the same department.
Brandon Lewis was appointed as Northern Ireland secretary, replacing the axed Mr Smith.
Former Brexit minister Suella Braverman returned to the Government as attorney general.
Ex-Brexit secretary Stephen Barclay has replaced Mr Sunak as chief secretary to the Treasury.
Amanda Milling was made Conservative Party chairman and she will attend Cabinet as a minister without portfolio.
Former defence secretary Penny Mordaunt returns to Government as paymaster general in the Cabinet Office.
Among the final ministerial changes, Paul Scully has been appointed as the new minister for London.