Prince Harry arrives at the High Court in London, June 6, 2023. (PHOTO / AP)

LONDON – Prince Harry will become the first senior British royal to give evidence in court for more than a century when he appears on Tuesday in his lawsuit against a publisher whose titles he accuses of phone-hacking and other unlawful activities.

Harry, the fifth-in-line to the throne, failed to show up as expected on Monday at London's High Court where he and more than 100 others are suing Mirror Group Newspapers (MGN), the publisher of the Daily Mirror, Sunday Mirror and Sunday People, over allegations of widespread wrongdoing between 1991 and 2011.

However, the younger son of King Charles will on Tuesday and Wednesday face hours of cross-examination in the witness box from Andrew Green, MGN's lawyer, over 33 newspaper articles he says were based on information which had been unlawfully obtained.

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It will make him the first senior royal to give evidence for 130 years.

MGN, now owned by Reach, did apologize at the start of the trial after admitting the Sunday People had unlawfully sought information about Harry on one occasion, and has previously admitted its titles were involved in phone-hacking, settling more than 600 claims

The MGN trial began last month, with lawyers for Harry and the other claimants seeking to prove that unlawful information gathering was carried out with the knowledge and approval of senior editors and executives.

Harry is one of four test cases, and his specific allegations form the focus of the first three days of this week.

However, Harry did not appear on Monday, having only left the United States, where he now lives with his American wife Meghan, the previous evening as it was his daughter Lilibet's birthday on Sunday. The judge, Timothy Fancourt, said he was surprised at his absence.

Subject of thousands of stories 

Setting out the argument, the prince's lawyer David Sherborne said Harry had been the subject of thousands of MGN stories since he was a young boy, and as such was a regular target of unlawful behavior, with his late mother Princess Diana, also a victim of hacking.

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Harry wanted to focus attention on the unlawful activities rather than because of a "vendetta" against the press, Sherborne said.

Britain's Prince Harry arrives at the Royal Courts Of Justice in London, March 28, 2023. (PHOTO / AP)

MGN, now owned by Reach, did apologize at the start of the trial after admitting the Sunday People had unlawfully sought information about Harry on one occasion, and has previously admitted its titles were involved in phone-hacking, settling more than 600 claims.

But Green, MGN's lawyer, said there was no evidence that Harry had ever been the victim of phone-hacking, let alone habitually as he claimed, and rejected he had been the victim of any further unlawful actions.

READ MORE: Tabloid apologises to Prince Harry at start of phone-hacking trial

Buckingham Palace is likely to feature prominently in Harry's cross-examination, with MGN arguing that some of the personal information involved had come from senior royal aides, including from one of his father's former top officials.

Ironically in his memoir, Netflix documentary series and other TV interviews, the prince has repeatedly accused his family and their aides of colluding with tabloids to enhance their reputations at his expense.

The palace has not commented on those accusations.