Less than three years on, the intensifying row between the Sussexes and Britain's royal family has captivated the globe.

Never before have we seen the monarchy machinery exposed quite so publicly.

If there were any doubts about the nature of Prince Harry and Meghan's interview with Oprah Winfrey, they disappeared this week.

In a preview clip released ahead of Monday's broadcast, the Duchess of Sussex accuses someone in the royal household of spreading lies about her.

"I don't know how they could expect that after all of this time we would still just be silent if there is an active role The Firm [royal family] is playing in perpetuating falsehoods about us," she said.

The sit-down with Oprah is expected to look at a range of issues including Meghan "stepping into life as a royal, marriage, motherhood, philanthropic work" as well as "how she is handling life under intense public pressure".

Only hours before the preview clip was released, Buckingham Palace issued an extraordinary statement saying it was "very concerned" about claims that Meghan had bullied Kensington Palace staff. The claims have been denied by the Sussexes.

It followed a leak to The Times newspaper which claimed the duchess had reduced staff to tears.

Whether the claims are true or not, whoever leaked them achieved their goal: to cast doubt on Meghan's character and lay the defensive groundwork in case the Oprah interview embarrasses the royals.

Harry and Meghan's decision to write their own story has been praised by some and denounced by others. And while the pair are unlikely to attack specific family members in Sunday's broadcast, the duo are now free from the shackles of royal protocols to disclose what led to their momentous departure.

So, how did it all go so horribly wrong? As we look back at the warning signs of trouble brewing between the Duke and Duchess and the rest of the royals there is a timeline:

July 2016 -- A whirlwind relationship

Their love story began in the summer of 2016 when Meghan Markle met up with Prince Harry for a drink on what was perhaps the most impressive blind date set-up in history.

They revealed later that neither knew much about the other: She wasn't particularly familiar with the royal family; while he hadn't seen the TV show "Suits" which Meghan starred in at the time. But they hit it off, quickly organizing a date for the very next day.

Just a few weeks later, and unbeknown to the world at that point, Harry convinced Meghan to join him in Botswana where they camped under the stars.

It was there the budding couple really got a chance "to get to know each other," Harry later said in the couple's engagement interview with the BBC.

Meghan added: "We were able to really have so much time just to connect, and we never went longer than two weeks without seeing each other, even though we were obviously doing a long-distance relationship. We made it work."

By November, rumours were circulating in British newspapers that Harry had a new girlfriend.

Like bloodhounds, the tabloid media sniffed out the relationship with Markle, with some outlets paying particular ugly attention to her heritage and status as a divorcee.

In an unprecedented move, Harry put out a blistering statement fiercely cautioning the press to reign their coverage in.

November 2017 -- Harry pops the question

Harry and Meghan pose for photographers in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement.

Sixteen months later, Harry's father, Prince Charles, jubilantly broke the news that the pair were engaged in a statement on Twitter and would marry in May 2019.

Shortly after the statement, Harry and Meghan appeared for a photo call on the grounds of Kensington Palace before filming an interview for the BBC.

Broadcast later that night, Meghan spoke highly of the royal family and how welcoming they had been to her.

"The family has been great, and over the past year and a half we've just had a really nice time getting to know them and progressively helping me feel a part of not just the institution but also part of the family," Meghan said.

March 2019 -- Meghan targeted online

Kensington Palace -- which represented both the Cambridges and the Sussexes at the time -- bolstered its social media operations in response to an uptick in racist online abuse targeting Meghan.

The family released a set of social media guidelines and the royal household turned to Instagram and Twitter for support in combating the online abuse.

Palace staff also told CNN at the time that it was committing more resources to removing comments regarding Meghan, as well as blocking abusive accounts.

Additionally, specialized software was deployed to filter out the n-word, as well as emojis of guns and knives.

March 2019 -- A separate household

The Queen gave Harry and Meghan her permission to set up their own office with its own staff at Buckingham Palace in the spring.

Some questioned if there had been a falling out between the senior royal couples but Kensington Palace insisted it was part of a "long-planned move."

The Sussexes had been living at Nottingham Cottage, a house within the grounds of Kensington Palace in London but were due to move to their new home at Frogmore Cottage on the Windsor Estate, west of London as they prepared for the arrival of their first child.

May 2019 -- Royal baby makes three

The Sussexes with their newborn son Archie Harrison Mountbatten-Windsor during a photocall in St George's Hall at Windsor Castle on May 8, 2019.

On May 6, Buckingham Palace announced the Duchess of Sussex had given birth to a boy. The first child of Meghan and Prince Harry was "delivered safely at 5:26 am" weighing 7lbs. 3oz, the palace said.

The customary ceremonial easel with a framed notice of birth was placed in the forecourt of Buckingham Palace hours after the palace statement.

"The Queen and the Royal Family are delighted at the news that Her Royal Highness The Duchess of Sussex was safely delivered of a son," it read.

News of the Sussexes' growing family had been revealed back in October as they embarked on their first overseas tour to Australia. 

June 2019 -- Sussexes split from joint charity with Cambridges

Whispers of a rift reemerged again with the announcement that Harry and Meghan were separating from the Royal Foundation, the charity set up for the brothers in 2011.

Royal aides said the decision was merely a reflection of the divergent paths the two couples were on and rejected any suggestion of divisions by confirming the so-called "Fab Four" would continue to appear together for official engagements.

October 2019 -- Meghan reveals pressures of royal life; Harry confirms conflict with William

The Duchess opened up about the intrusive media treatment she had endured since joining 'The Firm' in a powerful interview with British channel ITV news during the Sussexes' official tour of southern Africa.

"I never thought that this would be easy, but I thought that it would be fair," she told reporter Tom Bradby, a close friend of Prince Harry and his brother Prince William.

"I've really tried to adopt this British sensibility of a stiff upper lip," she said. "I tried, but I think what that does internally is probably really damaging."

In response to how she was feeling, Meghan said, not many people have asked if I'm okay, but it's a very real thing to be going through behind the scenes."

Many, including Bradby himself, in a subsequent article about the "Poisonous palace" -- interpreted the Duchess' response that "Not many people have asked" as a reference to the family and its staff.

In the same documentary, Harry acknowledged tensions with his brother William.

Mid-November 2019 -- Time to take a break

After completing a hectic run of public events, Harry and Meghan took some "family time" towards the end of the year.

Initially, their whereabouts were unknown before a spokesperson for the couple confirmed in December that the Sussexes had been spending time in Canada, where Meghan was based while on TV show "Suits."

January 2020 -- Stepping back and summits

Harry and Meghan announced that they were stepping back from their roles as senior royals in an apparently sudden move that caught both the public and palace off guard.

"After many months of reflection and internal discussions, we have chosen to make a transition this year" they said via their Instagram account, explaining that they hoped to "Carve out a progressive new role within this institution."

Discussions over the couple's future were already in hand privately and the Queen was said to have been "Disappointed" with her grandson over his public revelation, Palace sources said at the time.

As newspapers seized on a royal crisis, Queen Elizabeth stepped in and called a summit at her Sandringham estate, summoning Princes Charles, William and Harry to hash out the details.

A week later, the monarch announced she was "Pleased" to have "Found a constructive and supportive way forward for my grandson and his family. She acknowledged the challenges they had faced and said she supported "Their wish for a more independent life."

July 2020 -- Hints of unhappiness in court documents

Meghan disclosed in court documents from her successful invasion of privacy case against Associated Newspapers Limited (ANL), owners of the Daily Mail and Mail on Sunday newspapers, and MailOnline, among others, that she felt "Unprotected" by the monarchy during her first pregnancy.

Meghan was "The subject of a large number of false and damaging articles by the UK tabloid media, specifically by the defendant [ANL] which caused tremendous emotional distress and damage to her mental health," her lawyer wrote in legal filings.

"As her friends had never seen her in this state before, they were rightly concerned for her welfare, specifically as she was pregnant, unprotected by the Institution, and prohibited from defending herself," the lawyer wrote.

The legal documents were the first time Meghan had publicly indicated her unhappiness at the support Palace staff were providing to her.

February 2021 -- Door closed on royal return

As the end of the one-year transition period drew closer, friction reignited between the Sussexes now based in Los Angeles and the royals back home in the UK.

It was announced that Harry and Meghan had agreed with the Queen that they would not be returning as working members of the family.

As a result, their honorary military appointments and royal patronages were revoked.

How can I watch it in Australia?

Oprah With Meghan And Harry: A CBS Primetime Special will air on Channel 10 at 7:30pm on Monday 08-03-21.

You'll also be able to watch it on Channel 10's digital platform, 10 play.

CBS will play the interview in the US at 8:00pm Eastern Time — that will be 1:00am in London and midday AEDT.