There were other clear signs that Harry was no ordinary plaintiff. Photographers and camera crews jostled outside the court as he arrived. As he took his place on the stand, lawyers caucused briefly over how to address the witness, who also goes by the title Duke of Sussex. They settled on Prince Harry.

Harry is one of four plaintiffs in this case, one of only two civil suits rooted in the phone hacking scandal of 2011 that has made it all the way to trial. He is the first senior royal to testify in court since 1891, when the Prince of Wales, the future Edward VII, testified in the case of a man accused of cheating at a game of baccarat.

For the prince, whose reputation in Britain has been tarnished by his bitter rupture with the royal family, the trial was a rare opportunity to take a stand against a news media that has its own checkered reputation. Beyond the charges in the case, Harry views the trial as a platform to call for a sweeping reform of the British press.

In written testimony submitted by his lawyers, Harry said the state of the British press, like that of the British government, was at “rock bottom.” His blunt comment was yet another precedent-shattering move: Royals, by custom, never wade into political commentary.

To prevail on the legal case, however, Harry will have to convince the judge, Timothy Fancourt, that the Mirror Group intercepted his voice mail messages and those of people close to him, and used other unlawful means to gather information. Proving hacking could be a high bar, given how much time has passed since the Mirror articles cited by Harry were published.