Prince Harry flashes a smile as he arrives to court following no-show

Prince Harry smirked as he rolled up to the High Court of the Royal Courts of Justice in London to testify against Mirror Group Newspapers — just one day after being a no-show.

The Duke of Sussex, 38, looked calm and collected as he greeted his lawyer outside the High Court’s Rolls Building with a big grin on his scruffy face.

Harry was photographed fussing with his blazer, which he paired with a textured dark purple tie.

The redheaded royal notoriously sued the publishing powerhouse behind the Daily Mirror, Sunday Mirror and Daily Express for allegedly obtaining information about him by hacking his phone.

“Tabloids would routinely publish articles about me that were often wrong but interspersed with snippets of truth, which I now think were most likely gleaned from voicemail interception and/or unlawful information gathering,” he said in his witness statement Tuesday.

Harry said that he feels that within every relationship he has ever had throughout his life — whether with friends, girlfriends, his family or the army — “there’s always been a third party involved, namely the tabloid press.”

He continued, “Having seen me grow up from a baby (being born into this ‘contractual relationship’ without any choice) and scrutinized my every move, the tabloids have known the challenges and mental health struggles that I have had to deal with throughout my childhood and adult life and for them to then play on that and use it to their own advantage, I think is, well, criminal.”

Harry is the first senior British royal to give evidence in the witness box in more than a century.

Page Six exclusively reported that his estranged family members were “privately bracing” for his testimony ahead of the trial.

 “I can’t imagine anyone is pleased,” one highly placed palace source told us.

Another royal insider said, “Harry would see himself as fighting their battle too, to protect the reputation of the monarchy.

“But certainly, they [the royal family] avoid confrontation with the media in most instances. And litigation is so lengthy, stressful and unpredictable, not to mention expensive.

“You just have no idea what direction the other side is going to go in on and what they will dredge up.”

MGN’s attorney Andrew Green KC claimed in court that much of the information published about Harry in their stories was “disclosed by or on behalf of royal households or members of the royal family.”

Harry was already off to a rocky start after skipping out on the first day of the trial Monday.

“I’m a little surprised,” Justice Timothy Fancourt said, noting he had directed Harry to be in court for the first day.

The prince’s lawyer David Sherborne explained to the court that Harry was not available to give evidence that day after traveling from California on Sunday night.

“His travel arrangements are such and his security arrangements are such that it is a little bit tricky,” Sherborne said, according to Reuters.

Harry apparently missed the trial so he could be home to celebrate his daughter Princess Lilibet’s 2nd birthday Monday with his wife, Meghan Markle, and their 4-year-old son, Prince Archie.

Page Six was told that after celebrating his daughter’s big day Sunday, Harry arrived in London via commercial flight Monday morning. We hear he was never expected to give evidence until Tuesday and that he will remain in the UK for the next few days.

The trial against MGN officially began on May 10, just four days after Harry went stag to his father King Charles III’s coronation ceremony at Westminster Abbey in London.

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MGN apologized for one instance of unlawful information gathering that “warrants compensation,” fessing up to a journalist having hired a private investigator to illegally gather intel about Harry’s activities in a London nightclub in 2004.

But the instance was not one listed by Harry in his case, and MGN denied Harry’s phone hacking allegation.

“MGN unreservedly [apologizes] for all such instances of UIG and assures the claimants that such conduct will never be repeated,” the publisher’s statement said.

Harry’s trial involves 148 articles published between 1996 and 2010, according to the BBC.