It's being labelled by the British press as "the royal court case of the century."
This week, Prince Harry is set to testify in the first of his five pending legal cases largely centred around battles with British tabloids.
If the Duke of Sussex appears in the witness stand as scheduled in his lawsuit against the publisher of the Daily Mirror, he would become the first senior royal in 130 years to give evidence in court.
The last time a royal appeared in court was over a century ago when Edward VII testified as a witness in part of a divorce case in 1870 and 20 years later in a slander trial over a card game, both before he became king.
Prince Harry's legal move is allegedly against the wishes of his father, King Charles III.
Back in April, court documents filed by the prince said that the royal family had diligently avoided the courts to prevent testifying about matters that might be embarrassing.
Here's everything you need to know ahead of the historic court appearance.
But first, some context around Harry's history with the press
The Daily Mirror case is one of three Prince Harry has brought alleging phone hacking and other invasions of his privacy, dating back to when he was a child.
In court documents, Prince Harry has described his relationship with the press as "uneasy", but it goes further than that.
The prince blames the paparazzi for causing the car crash that killed his mother, the late Princess Diana.
"I think one of the hardest things to come to terms with is the fact that the people that chased her into the tunnel were the same people that were taking photographs of her while she was still dying on the back seat of the car," the prince told the BBC in 2017.
He also cites harassment and intrusion by the British Press and "vicious, persistent attacks" on his wife, Meghan Markle, including racist articles, as the reason the couple left royal life and fled to the US in 2020.
What is phone hacking?
Phone hacking is the illegal interception of voicemails on mobile phones.
The tactic first came to attention in 2006 when the then-royal editor of Rupert Murdoch's News of the World (NOW) tabloid and a private investigator were arrested.
They pleaded guilty and were jailed in 2007. The NOW and senior figures at Murdoch's News Group Newspapers (NGN) UK operation said hacking was limited to a rogue reporter.
But further revelations in 2011, including that a murdered schoolgirl had been targeted, led to the closure of the paper and a criminal trial.
The Mirror group had consistently denied its journalists had been involved in hacking, including at a public inquiry, but in 2014 it admitted liability in four cases.
Since then, MGN has settled more than 600 claims at a cost of over 100 million pounds ($188 million) in damages and costs.
Who is Harry suing?
The duke is taking on three of Britain's best-known tabloid publishers:
- Mirror Group Newspapers, publisher of Daily Mirror, Sunday Mirror and Sunday People
- Rupert Murdoch's News Group Newspapers, publisher of The Sun
- Associated Newspapers Ltd, which owns the Daily Mail and Mail on Sunday.
The claims are similar: that journalists and people they employed listened to phone messages and committed other unlawful acts to snoop on Prince Harry and invade his privacy.
Several celebrities with similar allegations have also filed claims being heard alongside Prince Harry's, including Hugh Grant in the News Group case, and Elton John and Elizabeth Hurley in the Associated Newspapers case.
Associated Newspapers "vigorously denies" the claims. News Group has apologised for News of the World's hacking but The Sun does not accept liability or admit to any of the allegations, according to spokespeople.
Both publishers argued during High Court hearings that the lawsuits should be thrown out because Prince Harry and the others failed to bring them within a six-year time limit.
But the lawyer representing Prince Harry and other claimants said they should be granted an exception because the publishers lied and concealed evidence that prevented them from learning of the covert acts in time to meet the deadlines.
What is this current court case about?
Prince Harry and more than 100 other people are suing Mirror Group Newspapers (MGN), accusing them of widespread unlawful activities between 1991 and 2011.
Those involved include actors, sports stars, celebrities and people who simply had a connection to high-profile figures.
They say its journalists or private investigators commissioned by them carried out phone hacking on an "industrial scale", obtained their private details by deception and carried out other illicit acts to find out information about them.
Senior editors and executives knew and approved of the behaviour, the claimants' lawyers say.
The court was told by a journalist and biographer of Prince Harry that one of those who knew about hacking was former editor Piers Morgan, now one of Britain's most high-profile broadcasters and an outspoken critic of the prince and his wife, Meghan.
Morgan, who has denied any involvement in unlawful behaviour and has accused Prince Harry of invading his own family's privacy, left his job as a presenter on a TV breakfast show after making outspoken remarks about Meghan.
MGN is contesting the claims and denies senior figures were aware of wrongdoing. It also argues some of the lawsuits were brought too late.
Prince Harry was selected at an earlier hearing as one of four test cases for the trial, which began on May 10.
What does Harry say the newspapers did?
Prince Harry says 140 stories which appeared in MGN papers were the result of phone hacking or other unlawful behaviour, however, the trial is only considering 33 of these.
His lawyers said the intrusion led to the breakdown of his relationship with long-term girlfriend Chelsy Davy.
In other documents released at the outset of the trial, MGN admitted there was evidence that private investigators had been instructed to unlawfully gather information about three of those involved in the test cases, including, on one occasion, Prince Harry.
The publisher said it unreservedly apologised and that he was entitled to compensation.
However, it has rejected his other claims. In documents, it says some of the information had been passed on by a former senior aide working for his father.
MGN's documents say one story about Prince Harry came when his father's former deputy private secretary and Morgan were having "regular meals and drinking sessions together".
Prince Harry has said that his family and their aides had been complicit in leaking negative stories to protect or enhance their own reputations.
The palace has not commented.
What has Harry said about his legal battles?
In a statement he wrote as part of his case against Murdoch's News Group Newspapers, Prince Harry said: "This isn't just about phone hacking, this is about accountability of power."
He says the press was too important to have "criminals masquerading as journalists running the show".
How might this end for Harry?
Sean Coughlan, the BBC's royal correspondent, wrote that Prince Harry has two of the "key requirements" for this courtroom showdown: "First, a single-minded determination to keep going without settling, and second, being rich enough to take the financial hit if he loses."
But Coughlan argues the duke's decision to give evidence in person is not without its risks, as it exposes the prince up to "tough questioning that is a long way from any previous royal interview he has taken part in."
David Yelland, a senior communications adviser and a former editor of Murdoch's Sun tabloid newspaper, said the royal family had long sought to avoid court cases because they were not in control of the situation.
"These cases are often a case of mutually assured destruction," he told Reuters.
"I don't think anyone will get out looking great."
