Prince Harry, the Duke of Sussex, accuses Associated Newspapers of hiring private investigators to bug cars and eavesdrop on him in landmark legal battle.

Prince Harry, the younger son of King Charles III, will take the stand Wednesday in a London courtroom. Harry is scheduled to testify in the privacy invasion case against publisher Associated Newspapers Limited, the publishers of the Daily Mail and Mail on Sunday. He is the first witness to be called in the trial, which began Monday.

Kate Middleton and Prince William had a joint away day in Scotland as Prince Harry stepped out for the second day in a row in London.

The Duke of Sussex arrived at London's High Court on Monday “confident and ready,” a spokesperson told NBC News ahead of his battle with the publisher of the Daily Mail.

LONDON -- Millions of dollars are on the line as Prince Harry returned to court on Monday for the third and final chapter in his legal quest to tame the British tabloids.

The Duke of Sussex’s legal team says alleged unlawful reporting had a “profoundly distressing effect” on Harry

Harry’s various legal issues and trials have been the primary cause of the breakdown in the relationship between Charles and Harry,” one royal expert said.

Prince Harry is wrestling with a profound sense of dislocation in California, sources told RadarOnline. com, as Meghan Markle draws an unmistakable line over her husband's desire to spend more time back in Britain.

Prince Harry shared a terse response after his first day in court, following his return to the U.K. for a trial against a major British publisher.