Prince Harry has begun giving evidence at London’s High Court in his lawsuit against a tabloid publisher whose titles he accuses of phone hacking and other unlawful activities.

Harry, the fifth-in-line to the throne, briefly smiled as he passed the phalanx of waiting photographers and camera crews when he arrived at the court building in central London on Tuesday ahead of the very rare court appearance by a royal.

He is first senior royal to enter the witness box in more than a century.

The prince had failed to show up as expected on Monday for the trial 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.

It makes him the first senior British royal to give evidence for 130 years. He will be giving his evidence from the same witness box in Court 15 where singer Ed Sheeran and French actress Eva Green have both recently appeared in separate and unrelated cases.

Harry swore on the bible and, before his cross-examination began, confirmed that he should be addressed as “Your Royal Highness” in the first instance and that his personal preference was to be called “Prince Harry” afterwards.

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, he did not appear on Monday, having only left the United States, where he now lives with his 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.