Mr Sunak will be appointed as the country’s next prime minister by the King on Tuesday.
Timeline
Three prime ministers inside seven weeks – how did that happen?
Here is a timeline of the recent political crises which engulfed the leadership of two prime ministers and ultimately led to their downfall.
Partygate to Pincher: Johnson considers comeback despite year of scandals
The ex-PM was forced to quit by his own MPs after a series of political crises.