It was, perhaps, the most significant announcement about the future of the Royal family for almost three decades.
And in a glimpse of the disaffection with tradition that partly lay behind their move, the public were informed of the Duke and Duchess of Sussex's decision to renounce their royal titles in a post on the couple's Instagram page, at 6.30pm yesterday.
The post itself conveyed a heartfelt statement by the Queen that appeared to speak as much as a loving grandmother as a monarch concerned about the future of the Royal family.
The Queen said she was "pleased that together we have found a constructive and supportive way forward for my grandson and his family", following their wish "for a more independent life".
A separate statement from Buckingham Palace revealed that the Duke and Duchess - whom the Queen said had "so quickly become one of the family" - would step back from royal duties, including official military appointments, give up their His and Her Royal Highness titles, and no longer formally represent the monarch.
Here, The Sunday Telegraph details the key changes agreed as part of the deal between the couple and their family, and their significance to the Duke and Duchess:
The Sussexes, who will now go by Harry, Duke of Sussex and Meghan, Duchess of Sussex, will give up their HRH style - which Prince Harry has had since birth and Meghan since their marriage on May 19, 2018.
Some royal watchers had predicted that the couple may have been preparing to surrender the style after it emerged that their son Archie, born on May 6 last year, had been given no title.
Joe Little, the managing editor of Majesty magazine, said: "The fact Archie isn't Earl of Dumbarton or styled HRH makes me wonder whether this wasn't already part of a wider masterplan."
The Duke and Duchess of Sussex have indicated they will spend the majority of their time in North America, but retain Frogmore Cottage as a UK base, and that they will pay commercial rent on the home.
Taxpayers paid £2.4 million to renovate the cottage, which the couple moved into just nine months ago - leaving Kensington Palace, which only fanned rumours of a rift with the Cambridges.
The couple have agreed they will pay the Sovereign Grant cost of the refurbishment back to the public purse.
Work on the property in the Berkshire property overran and it was reported that the couple made constant design changes, meaning the builders fell behind schedule.
Their new website sussexroyal.com says the Duke and Duchess moved to Windsor for "various reasons", and that their previous residence of Nottingham Cottage in the grounds of Kensington Palace "could not accommodate their growing family".
There is now expected to be a short "transition period" during which the couple will divide their time between Britain and Canada, before spending the majority of time in North America.
The Duchess is on Vancouver Island with their eight-month-old son Archie, and the Duke is expected to join her there soon.
The announcement that the Duke of Sussex will lose his military patronages comes as a significant blow to the prestige that he has enjoyed until now.
Prince Harry's military titles and patronages include that of Captain General of the Royal Marines, a position he was understood to have been particularly proud of, having been appointed in December 2017, when he succeeded his grandfather, the Duke of Edinburgh, in the role.
He will now also lose the other military titles and patronages which he has been awarded since serving two tours of Afghanistan with the British Army, where he rose to the rank of Captain.
These are: Honorary Air Commandant of RAF Honington; and Commodore- in-Chief, Small Ships and Diving.
One of the major roles lost by the Duke of Sussex in his deal with Buckingham Palace is Commonwealth Youth Ambassador, which had been the focus of several overseas tours.
The Duke was appointed to the position by the Queen in 2018 with a view to helping young people use "Commonwealth platforms" to address social, economic and environmental challenges facing their generation.
It was work that the sixth in line to the throne pursued with zeal. Last year, he visited South Africa, Angola and Malawi on an official diplomatic engagement in the role.
Prince Harry had also seen it as part of his future work with his wife. In his first speech in April 2018, he said he was "incredibly grateful" that the woman he was, at that point, about to marry, would join him in the job.
The role of youth ambassador - his most high-profile at the time - is considered particularly important because of the Commonwealth's demographic, with 60 per cent of the population of its 53 member nations being under the age of 30.
Despite Harry stepping back from the position, he and Meghan will remain president and vice-president respectively of the Queen's Commonwealth Trust.
Buckingham Palace will not comment on the couple's future security arrangements save to say these will be determined by well-established risk assessments carried out by the police and security services.
But experts have warned that taxpayers will need to fund police protection for the Duke and Duchess of Sussex for years to come.
They fear couples will continue to be at risk from terror groups, political fanatics and lone obsessives long after they separate from the Royal family.
Dai Davies, who was head of Royal Protection from 1994 to 1998, said: "We don't want the situation where Harry and Meghan are being followed, without protection, by paparazzi or people with a fixation and we need to be sure that protection is of the highest level."
Ministers and senior police officers are thought to be determined to avoid the mistakes made over Diana, Princess of Wales, who in 1993 turned down police protection except when she was with her sons or staying at Kensington Palace.
That left her relying on private security at other times, leading to her being in the hands of the Ritz Hotel's head of security Henri Paul on the night she died when their car crashed in the Pont de l'Alma underpass as he tried to evade photographers.
What they can keep
As Harry, Duke of Sussex and Meghan, Duchess of Sussex, the newly-independent couple will retain many of their patronages in a private capacity.
The Duchess, who has made clear her intention to continue to work on causes relating to female empowerment, remains as patron of SmartWorks, a charity which provides clothes and mentoring to disadvantaged women seeking employment.
She is also patron of the National Theatre, animal charity Mayhew and The Association of Commonwealth Universities.
Prince Harry will continue to work with his key charities, including the Invictus Games and Sentebale, which helps children affected by HIV in Lesotho and Botswana.
Others close to his heart include WellChild, which supports families caring for seriously ill children, and African Parks, a conservation charity.
He remains 6th in line to the throne, with Archie Mountbatten-Windsor at 7th. He is also expected to appear at several scheduled engagements in the UK before the new arrangement takes effect in spring 2020.
What is to come for the Duke and Duchess of Sussex remains uncertain, with many details still yet to be agreed.
The SussexRoyal branding, under which they operate their social media, has already been copyrighted, but aides were last night unable to say whether they would retain it as non-working members of the Royal family.
Experts have pointed out that their official branding could allow them to make millions as a direct result of their former status.
Buckingham Palace will no longer have influence or oversight of the Sussexes' working lives, leaving serious questions about whether the couple can continue to operate as "SussexRoyal".
A source said the couple have not yet secured any commercial deals.The couple's foundation, due to launch later this year, may also need to be renamed.
Although they will no longer automatically be part of official public events, they are likely to appear at family occasions at the invitation of the Queen.
Aides have not yet indicated whether they will appear on the balcony at Buckingham Palace for Trooping the Colour, at Remembrance events or occasions such as Royal Ascot.
Last night, the couple's website, sussexroyal.com, published a promise to update "information on the roles and work of The Duke and Duchess of Sussex...in due course".