He's spent nearly two decades working with Conservative politicians in the upper reaches of government - but many of us hadn't heard of Dominic Cummings until his infamous lockdown trip to Barnard Castle earlier this year. Now that the prime minister's chief adviser is leaving Downing Street, we look back at some memorable moments in his career.
1. Barnard Castle
Mr Cummings became a household name after he defended his 260-mile drive from his home in London to his parents' farm in County Durham during the UK's national coronavirus lockdown in March.
Following pressure from all political sides to explain why he went against the government's "stay at home" messaging, Mr Cummings said he made the journey for childcare reasons after his wife developed coronavirus symptoms.
But a subsequent outing, this time from the cottage on his parents' farm to the historic market town of Barnard Castle, was the trip that gave fuel to meme-makers across the country. Mr Cummings said the reason for that trip was to test his eyesight and his readiness to drive back to London.
2. Brexit bus
The success of the Vote Leave campaign in the 2016 EU referendum no doubt helped to secure Mr Cummings' job in Downing Street, as it was his role during that which cemented his strong bond with Boris Johnson.
Mr Cummings, the campaign's director, was credited with the "take back control" slogan that appeared to strike a chord with so many referendum voters, as well as the claim that Britain could save £350m a week by leaving the EU.
3. Infamous insults
In addition to his snappy slogans, Mr Cummings has also hurled some infamous insults at politicians - often through the medium of his personal blog. For example, he has said:
- Brexit Secretary David Davis is "thick as mince" and as "lazy as a toad"
- Computer-animated superhero team PJ Masks would do a better job than the cabinet
- MPs who want to disrespect the EU referendum result are "pirates"
- Some MPs who wanted to leave the EU were "idiots" and should be treated like a "tumour"
4. 'Weirdo' recruitment drive
Mr Cummings' blog also drew headlines when he used it to tout his ideas to shake up the civil service.
In a blog post in January this year, he said the civil service lacked people with "deep expertise in specific fields" and called for "weirdos and misfits with odd skills" to get in touch with him via a private Gmail address if they wanted to work in government.
The post stoked tensions, with the civil servants' union saying staff were recruited on merit and "because of what you can do, not what you believe".
5. Not-so-civil service
The clashes with other civil servants reached new heights after a special adviser was sacked and escorted out of Downing Street by police, following a confrontation with Mr Cummings.
No reason was given for Sonia Khan's dismissal in August 2019, but it's thought she had been accused by Mr Cummings of leaking details of a no-deal Brexit exercise to the media.
Her then-boss (and then-chancellor) Sajid Javid "voiced his anger" with the PM over her treatment, later resigning when Mr Johnson ordered him to fire his team of aides. Labour said Mr Javid's departure showed Mr Cummings had "won the battle to take absolute control of the Treasury".
6. Grand designs
This is perhaps a lesser-known highlight, but it's a highlight all the same.
According to Buzzfeed News, Mr Cummings was greatly frustrated by the prime minister's rejection of his proposal to change Downing Street's office layout.
The top aide wanted to knock walls through and put desks in circles around both him and Mr Johnson, who would sit in the centre, the Buzzfeed report claims.
The news site claims the plans were rejected as unworkable - in part as a result of No 10's status as a Grade One listed building.
7. Hollywood makeover
The penny must drop that you've had an interesting career when you hear an Oscar-nominated actor is preparing to play you in a TV drama.
Benedict Cumberbatch's portrayal of Mr Cummings in Channel 4's Brexit: The Uncivil War was as - in the words of our arts editor - "an intense, socially awkward, strategic mastermind with a gentle Durham accent and a penchant for hanging out in stationery cupboards at work".