Prince Harry arrived at a London court to testify against a tabloid publisher Tuesday, making him the first royal to enter a witness box in centuries.

LONDON (AP) — Prince Harry is due at a London court Tuesday to testify against a tabloid publisher he accuses of phone hacking and other unlawful snooping. Harry alleges that journalists at the Daily Mirror and its sister papers used unlawful techniques on an “industrial scale” to get scoops.

Prince Harry took the stand in a case against the British tabloid newspaper “Daily Mirror” and more on June 6. He said journalists have “blood on their hands.”

Prince Harry testified in London on Tuesday as part of the phone hacking lawsuit he brought against Mirror Group Newspapers, alleging that the tabloid press had hacked his phone and voicemails and those of his friends and associates to illegally obtain information about him.

Prince Harry appeared in court to give testimony in his case against Mirror Group Newspapers. On Tuesday morning, the Duke of Sussex arrived at the High Court of the Royal Courts of Justice in London to give evidence supporting his case against Mirror Group Newspapers (MGN).

As part of his mission to rein in the tabloid media, Harry is testifying and being cross-examined over at least two days in his suit against the Daily Mirror.

Prince Harry took the stand in a London courtroom, testifying in his lawsuit against Mirror Group Newspapers, who the duke claims used "unlawful information gathering" against him for decades. NBC News’ Meagan Fitzgerald breaks down the main takeaways from Prince Harry’s testimony and how attorneys for the Mirror Group Newspapers are responding to his allegations.