Here are details of the case:

WHAT IS THE COURT CASE ABOUT?

Harry and more than 100 other people are suing Mirror Group Newspapers (MGN), publisher of the Daily Mirror, the Sunday Mirror and the Sunday People tabloids, 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 the media group's journalists or private investigators commissioned by them carried out phone-hacking on an "industrial scale" and obtained private details by deception.

Senior editors and executives knew and approved of the behaviour, the claimants' lawyers say. MGN is contesting the claims and denies senior figures were aware of wrongdoing. It also argues some of the lawsuits were brought too late.

Harry, the younger son of King Charles, was selected at an earlier hearing as one of the test cases for the trial which began on May 10.

Since it began, MGN has admitted private investigators had been instructed to unlawfully gather information about three of those involved in the test cases, including, on one occasion, Harry.

The publisher said it unreservedly apologised and that the prince was entitled to compensation. But it denies any other wrongdoing in relation to him, saying there was no evidence for it.

WHAT IS PHONE-HACKING?

Phone-hacking, the illegal interception of voicemails on mobile phones, first came to public 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 the 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.

In 2014, the NoW's former editor, Andy Coulson, who later worked for ex-Prime Minister David Cameron, was found guilty of conspiracy to hack phones and jailed. Rebekah Brooks, who heads up Murdoch's UK newspaper and radio operation, was acquitted of all charges.

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. The following year the High Court awarded eight individuals a total of 1.2 million pounds in damages after ruling they were victims of hacking.

Since then, MGN has settled more than 600 claims at a cost of over 100 million pounds ($120 million) in damages and costs.

WHAT DID HARRY SAY IN COURT?

The fifth-in-line to the throne became the first British royal to appear in the witness box since the 1890s when he gave evidence over two days at the start of June.

Harry says he was targeted by MGN for 15 years from 1996 with 140 stories which appeared in its papers were the result of phone-hacking or other unlawful behaviour, although the trial is only considering 33 of these.

He blames the intrusion for the breakdown of his relationship with a long-term girlfriend, Chelsy Davy, and that MGN had sown the distrust in Harry's relationship with his elder brother Prince William, with whom he has since fallen out.

His evidence also touched on his drug use as a teenager and the "hurtful" rumours that his real father was Major James Hewitt, with whom his mother had a relationship.

Andrew Green, MGN's lawyer, put it to him that some of the personal information in the stories had come from, or was given with the consent of, senior Buckingham Palace aides, or was simply based of details already made public in other articles.

Asked if he would be disappointed if the court ruled he was not a victim of hacking, Harry replied; "Nobody wants to be phone hacked" but said he would feel "some injustice" if that was the conclusion.

He also disclosed that he had decided on taking the legal action against MGN and other publishers after a chance meeting with his lawyer David Sherborne in France.

PIERS MORGAN INVOLVED?

A number of witnesses, including Harry himself, implicated senior figures from MGN as being involved in phone-hacking or at least aware it was going on. The most notable was Piers Morgan, now a very high-profile TV presenter, who edited the paper between 1995 and 2004.

The Mirror's former Group Political Editor David Seymour and Omid Scobie, who worked on the tabloid and later penned a biography of Harry, were among those who pointed the finger at Morgan in their evidence.

Morgan has always denied any involvement in, or knowledge of phone-hacking and said he would not "take lectures on privacy invasion from Prince Harry".

At the conclusion of putting the claimant's case, the judge, Timothy Fancourt, queried if Morgan and others, such as former Sunday People editor Neil Wallis, could and should have given evidence themselves.

"I perhaps ought to say that I am aware that both Mr Morgan and Mr Wallis have relatively recently had a good deal to say about this matter outside court, so the question as to why they're not here to give their evidence is of particular significance, I think," Fancourt said.

Harry and the other claimants lawyers have asked Fancourt to specifically rule on whether Morgan and other former editors were engaged in phone hacking or unlawful information gathering.

HARRY'S OTHER CASES

The MGN case is one of four that Harry is currently pursuing at the High Court against British newspapers.

He is also suing Murdoch's NGN, which publishes the Sun tabloid and used to produce the defunct NoW, over alleged phone hacking and other unlawful acts. NGN denies the Sun was involved in wrongdoing and is fighting to have his case thrown out.

The prince, with singer Elton John and five others, is also suing Associated Newspapers (ANL), publisher of the Daily Mail and Mail on Sunday, over phone hacking and illicit privacy breaches. ANL denies any unlawful activity.

Harry is also suing ANL for libel.

(Reporting by Michael Holden and Sam Tobin, editing by Ed Osmond)