Britain's Duke and the Duchess of Sussex announced on Tuesday that they would take legal action against the Mail on Sunday after it published one of Meghan Markle's private letters.
In an emotionally charged statement on the royal couple’s official website, Prince Harry said they made the decision after the “painful impact of relentless propaganda” against his wife from the British tabloid press.
The prince referred to past press coverage of his mother Princess Diana, saying he feared “history repeating itself”.
Diana became one of the most photographed women on the planet after she married into the British royal family.
She died in a car crash in Paris in 1997 after being followed through the streets by press photographers. Her funeral was watched by hundreds of millions of people around the world.
“Though this action may not be the safe one, it is the right one,” Prince Harry said.
A spokeswoman for the law firm handling the case told PA the lawsuit alleges the Mail on Sunday's "intrusive" publication of the letter was copyright infringement, misuse of private information and a breach of data-protection law.
Prince Harry accused the Mail on Sunday of editing out parts of the letter in "an intentionally destructive manner" to "manipulate" readers and provide an inaccurate picture of his wife.
A spokesman for the Mail on Sunday was not immediately available for comment.
The royal couple have been touring southern Africa with their baby son, Archie.
The prince visited the same landmine clearance project in Angola that Princess Diana had been to a few months before her death.
Harry, 35, Queen Elizabeth's grandson and sixth in line to the throne, said the legal action had been "many months in the making".
