Meghan Markle was the American actress, with a passion for humanitarian and feminist causes. Harry was the rebel prince turned soldier, considered the world's most eligible bachelor.
In the summer of 2016, the two were brought together on a blind date by a mutual friend in London.
"Beautiful" Meghan "just tripped and fell into my life", Harry later told the press, and he knew immediately she was "the one".
After just two dates, the new couple went on holiday together to Botswana, camping out under the stars.
They fell in love "so incredibly quickly", proof the "stars were aligned", said Harry.
To the British press, their romance was catnip. Here was a golden couple who were able to draw vast crowds, speak the language of younger generations and sprinkle royal stardust on any cause.
For months the couple avoided the cameras and it wasn't until the 2017 Invictus Games in Toronto that the the two were first photographed holding hands in public, smiling and laughing.
But there had been signs early on that the fairytale was some way off a "happily ever after".
When Harry first confirmed the relationship in late 2016, it came with a stark attack on the media, accusing them of subjecting his girlfriend to "a wave of abuse and harassment".
He spoke of nightly legal battles to keep defamatory stories out of papers, attempts by reporters and photographers to get into Meghan's home and the "bombardment" of nearly every friend and loved one in her life.
It was a problem that was only going to get worse.
Despite that - or perhaps because of that - the two grew ever closer and in September 2017, Meghan declared to Vanity Fair magazine: "Personally, I love a great love story."
The two of them had been enjoying a special time together and were really happy and in love, she said.
The media was now on high alert for the sound of royal wedding bells - and they didn't have to wait long.
In November 2017, Harry got down on one knee to propose to Meghan as they made roast chicken together at their home in Kensington Palace.
Harry had designed the ring, made with two diamonds which had belonged to his late mother, Diana, Princess of Wales. At the centre was a diamond from Botswana.
The couple shared their story in a candid interview with the BBC, and appearing brimming with positivity for the future.
They revealed Meghan would give up acting to focus on causes close to her heart, working alongside her husband-to-be.
"I know that she will be unbelievably good at the job part of it," said Harry.
Things began to shift as preparations got under way for a May 2018 wedding in Windsor.
It quickly became clear that this was a royal couple who wanted to do things differently - their way.
The wedding, which much of the world tuned in to watch, had all the traditions - a stunning dress, cheeky bridesmaids and heartfelt vows.
But, as our royal correspondent Jonny Dymond said at the time, the service with its gospel choir, young black cellist and breathtaking address from Bishop Curry, marked it out as a modern, diverse wedding for a modern, diverse couple, which seemed to point to a different future for the Royal Family.
Married life brought with it new titles - the Duke and Duchess of Sussex - and a new home at Windsor in Frogmore Cottage.
In October of that year, the couple embarked on their first royal tour, visiting Australia, New Zealand, Fiji and Tonga, over 16 days. It was there that they shared the news that they were expecting their first baby.
Archie Harrison Mountbatten-Windsor, seventh in line to throne and the Queen's eighth great-grandchild, was born on 6 May 2019.
To Harry, who was by Meghan's side at the birth, little Archie was "absolutely to die for".
Throughout Meghan's pregnancy, the continual redrawing of battlelines had gone on between the press and the couple.
This was to be no repeat of the Duchess of Cambridge's birth with the circus of journalists and photographers lying in wait outside hospital doors for days on end.
The press had been told there would be no information about the birth, beyond that it was happening.
Such scrutiny and pressure proved to be a struggle for the newly-wed Meghan during her pregnancy and in early motherhood, she later admitted in an ITV documentary filmed during their tour of southern Africa in September.
"Not many people have asked if I'm OK," she said, looking lost. She spoke of her vulnerability during pregnancy and the challenges of having a new-born - "it's a lot".
Asked if she could cope, she said she had long told Harry it was not enough to just survive - "that's not the point of life - you have got to thrive".
There were further signs that the couple were not happy, when the prince opened up about his mental health.
He said it was under constant management and he lived with the pressures of avoiding a repeat of the past that took his mother, the Princess of Wales, from him.
She died in a car crash in Paris when Harry was just 12. The driver had been drinking and the car was being followed by paparazzi on motorbikes.
"Everything that she went through, and what happened to her, is incredibly important every single day, and that is not me being paranoid," he said.
"Part of this job is putting on a brave face but, for me and my wife, there is a lot of stuff that hurts, especially when the majority of it is untrue," he added.
It has also been suggested the scrutiny of Meghan has been greater because of her African-American heritage.
The couple's frustration and anger with some sections of the press has gone from being a matter between the palace and editors into the full glare of the public spotlight.
Meghan is suing the Mail on Sunday over a claim that it unlawfully published one of her private letters and Harry filed proceedings at the High Court against the owners of the Sun, the defunct News of the World, and the Daily Mirror, in relation to alleged phone-hacking.
As such a dramatic year came to a close, the royal couple took an extended break from royal duties over Christmas, taking Archie to the Canadian province of British Columbia.
It gave them time to mull over their next move and, within days of the start of a new decade, they dropped their bombshell announcement.
Neither Harry's father, Prince Charles, nor his older brother, Prince William, with whom Harry has said he has "good days" and "bad days", were consulted.
Harry and Meghan were, they told their Instagram followers, planning to leave their royal duties - and the royal purse - behind.
They hope their next chapter, spent in North America as well as the UK, will see the two of them, together with baby Archie, make their own path to the future.