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 are having an away day in Scotland.

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.

Prince Harry is back in court in London as he and other high-profile figures accuse Associated Newspapers of illegal information gathering practices.

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 being accused of only wanting to make amends with King Charles III to validate his brand. Keep reading to learn more.