He says he acted "reasonably" and within the law by making his 260 mile journey to Durham, however, many say lockdown rules should have kept him, his wife and their son in isolation at home for 14 days.
March 23: Boris Johnson orders UK-wide coronavirus lockdown
In an address to the nation on the evening of Monday, March 23, Boris Johnson announced lockdown in the UK and declared a "national emergency".
These were shopping for basics, one form of exercise a day, travelling to and from work, but only where absolutely necessary, and medical needs.
Mr Johnson added: "If you don’t follow the rules the police will have the powers to enforce them, including through fines and dispersing gatherings."
Government guidelines stated: "You should not be visiting family members who do not live in your home."
At the time, the advice was that anyone with symptoms should isolate for seven days, with a 14-isolation for those around them.
March 27, 11:15am: Prime Minister Johnson - Mr Cummings' boss - announces he's been diagnosed with coronavirus
Mr Johnson posted a video to Twitter, announcing he'd "tested positive for coronavirus", and said he'd be self-isolating and working from home as a result.
March 27, around an hour later: Mr Cummings is seen running out of Downing Street
Shortly after Mr Johnson said he'd tested positive, Mr Cummings was caught on camera running out of 10 Downing Street.
The bizarre video showed the chief advisor running, with a backpack, toward a Downing Street exit out of the camera's sight.
Minutes after the video was posted to Twitter, Health Secretary Matt Hancock posted his own video, revealing he too had coronavirus.
By the end of the day, it transpired that the PM, the health secretary, the Chief Medical Officer Chris Whitty and Scottish Secretary Alister Jack were all self-isolating with coronavirus.
March 30: Downing Street confirms Mr Cummings is self-isolating
Following reports, Number 10 confirmed Mr Cummings and his wife Mary Wakefield had started showing symptoms of coronavirus “over the weekend”.
The spokesman said Mr Cummings was self-isolating and staying in contact with Downing Street. He was not tested for coronavirus.
Reports say around this time Mr Cummings made his trip to Durham.
March 31: Police made aware of Mr Cummings' trip
On March 31, Durham police are "made aware of reports that an individual had travelled from London to Durham and was present at an address in the city".
The force says officers "made contact with the owners of that address who confirmed that the individual in question was present and was self-isolating in part of the house".
"In line with national policing guidance, officers explained to the family the arrangements around self-isolation guidelines and reiterated the appropriate advice around essential travel."
Number 10 denied this was the case, saying: “At no stage was he [Mr Cummings] or his family spoken to about this matter, as is being reported.”
April 5: Mr Cummings is 'spotted in his father's garden'
Mr Cummings was reportedly spotted in his dad's garden, just days after contact from police.
A neighbour told the Daily Mirror he got the "shock" of his life when he "looked over to the gates and saw him".
April 5: Scotland's chief medical officer resigns after visiting her second home
Dr Calderwood said she was "truly sorry" for not following the advice she had been giving to others to stay at home.
Between around March 30 and April 6: Mr Cummings becomes very ill with coronavirus symptoms
Dominic Cummings' wife Mary Wakefield, editor of Tory magazine the Spectator, wrote an article, published on April 23, which revealed Mr Cummings had become very poorly.
"Day in, day out for ten days he lay doggo with a high fever and spasms that made the muscles lump and twitch in his legs. He could breathe, but only in a limited, shallow way," she wrote.
She added: "The little oxygen reader we’d bought on Amazon indicated that he should be in hospital, but his lips weren’t blue and he could talk in full sentences."
April 12: Mr Cummings and wife make trip to Barnard Castle
Mr Cummings and his wife were spotted 30 miles away from Durham in Barnard Castle by a member of the public, who passed the information to the Daily Mirror and Guardian.
"My wife was very worried, particularly as my eyesight seemed to have been affected by the disease," he said.
“We agreed that we should go for a short drive to see if I could drive safely, we drove for roughly half an hour and ended up on the outskirts of Barnard Castle town.
“We did not visit the castle, we did not walk around the town.”
The witness who saw him at Barnard Castle, Robin Lees, told ITV News there is "nothing wrong with my eyesight," adding, "not sure driving to test your eyesight is on".
April 12 is also listed as Mary Wakefield's birthday. April 12 2020 would have been her 45th birthday.
April 14: Mr Cummings returns to work
Mr Cummings returns to work for the first time since news he was suffering from coronavirus emerged.
Questions are raised about his adherence to social distancing advice as he is photographed walking in Downing Street with fellow aide Cleo Watson.
April 19: Mr Cummings reportedly spotted again in Durham
An unnamed witness apparently sees Mr Cummings out walking with his wife in Durham, recognising him by his trademark beanie hat and overhearing him remarking that the bluebells are "lovely".
The claim is reported by the Observer and Sunday Mirror on May 24.
In his press conference, Mr Cummings denies he made the second trip to Durham.
May 4: Top government scientist resigns for flouting lockdown rules
Epidemiologist Professor Neil Ferguson, who was instrumental in the government decision to impose the lockdown, resigned from Sage after allowing a lover to visit him at home.
Health Secretary Matt Hancock said it was "right" for him to resign from the scientific advice board, adding it was “just not possible” for him to continue advising the government.
May 13: Lockdown rules change in England
The government lifts the restriction on how far people can drive to reach the countryside and take exercise, but visits and overnight stays to second homes remain prohibited.
May 22: News breaks of Mr Cummings trip to Durham
A joint investigation between the Daily Mirror and the Guardian revealed Mr Cummings had made the trip to Durham.
Downing Street offered no initial comment on the story, but a source close to Mr Cummings said: "He isn’t remotely bothered by this story, it’s more fake news from the Guardian.
"There is zero chance of him resigning."
May 23: Boris Johnson and ministers stick by Mr Cummings
Downing Street issues a statement claiming Mr Cumming's journey was "essential", despite lockdown rules stating he should have stayed at home.
The statement said: "Owing to his wife being infected with suspected coronavirus and the high likelihood that he would himself become unwell, it was essential for Dominic Cummings to ensure his young child could be properly cared for."
Speaking to reporters outside his home, Mr Cummings said: "I behaved reasonably and legally."
When a reporter suggests his actions did not look good, he replies: "Who cares about good looks? It’s a question of doing the right thing. It’s not about what you guys think."
Later at the daily Downing Street briefing, Transport Secretary Grant Shapps said Mr Cummings has the PM’s "full support".
Throughout the day several government ministers defended Mr Cummings on Twitter, claiming he was right to "protect" his family.
Chancellor Rishi Sunak, Foreign Secretary Dominic Raab, Health Secretary Matt Hancock and Chancellor of the Duchy of Lancaster Michael Gove are among some of the most senior Tories to support Mr Cummings.
May 24: PM holds press conference defending Mr Cummings but backbenchers call for resignation
Mr Johnson told the press conference he firmly backs Mr Cummings, saying his aide acted in the best interests of his child, in a way "any parent would frankly understand".
He added: "I have concluded that in travelling to find the right kind of childcare, at the moment when both he and his wife were about to be incapacitated by coronavirus – and when he had no alternative – I think he followed the instincts of every father and every parent.
“And I do not mark him down for that.”
His comments followed calls from Tory MPs including prominent member of the 1922 Committee, Steve Baker.
Mr Baker became the first Conservative MP to publicly say Mr Cummings “should resign and should resign now".
Tory MP Sir Roger Gale also described Mr Cummings' position as "untenable".
Damian Collins joined the calls for Mr Cummings to go, saying: "The government would be better off without him."
May 25: Mr Cummings holds a very rare press conference
The prime minister's top aide attempted to justify his trip to Durham by holding his own press conference.
Mr Cummings said in a statement in the Downing Street rose garden: “I believe in all the circumstances I behaved reasonably and legally."
Furthermore, Mr Cummings denied he had broken the “spirit” of the rules and said he had not offered his resignation to the prime minister.
Mr Cummings said his decision to drive 264 miles from London to County Durham was based not only on fears over a lack of childcare if he became incapacitated with Covid-19 but also concerns about his family’s safety.
“I don’t regret what I did," he said, "I think reasonable people may well disagree about how I thought about what to do in the circumstances, but I think what I did was actually reasonable in these circumstances.
“The rules made clear that if you are dealing with small children that can be exceptional circumstances.
“And I think that the situation that I was in was exceptional circumstances and the way that I dealt with it was the least risk to everybody concerned if my wife and I had both been unable to look after our four-year-old.”
Mr Cummings admitted travelling to Barnard Castle by car to test if he was fit to drive the full journey back to London due to concerns over his vision after recovering from illness.
April 26: Scotland minister resigns over government response to Mr Cummings' trip
In a statement, Mr Ross said: "I have never met Dominic Cummings so my judgement on this matter has always been open and I accept his statement on Monday afternoon clarified the actions he took in what he felt were the best interests of his family.
"However, these were decisions many others felt were not available to them."
He added: "I have constituents who didn't get to say goodbye to loved ones; families who could not mourn together' people who didn't visit sick relatives because they followed the guidance of the government.
"I cannot in good faith tell them they were all wrong and one senior advisor to the Government was right."