A newspaper invaded the Duchess of Sussex’s privacy by publishing a personal letter to her estranged father, a British judge ruled Thursday, in a major victory for the royal in her campaign against what she sees as media intrusion.

The former American actress Meghan Markle, 39, sued publisher Associated Newspapers for invasion of privacy and copyright infringement over five February 2019 articles in the Mail on Sunday and on the MailOnline website that published large portions of a letter she wrote to her father after her 2018 wedding to Prince Harry.

High Court judge Mark Warby ruled that the publisher had misused the duchess’s private information and infringed her copyright.

He said the duchess “had a reasonable expectation that the contents of the letter would remain private. The Mail articles interfered with that reasonable expectation.”

Meghan said she was grateful to the court for holding Associated Newspapers to account “for their illegal and dehumanizing practices.”

She said that “with this comprehensive win on both privacy and copyright, we have all won.”

Associated Newspapers said it was “very surprised by today’s summary judgment and disappointed at being denied the chance to have all the evidence heard and tested in open court at a full trial.”

“We are carefully considering the judgment’s contents and will decide in due course whether to lodge an appeal,” said the publishing company, which had strongly contested Meghan’s claim.

A trial in the case, scheduled for the fall, would have been one of the most high-profile civil legal showdowns in London for years. But at hearings last month, lawyers for the duchess asked for a summary judgment to settle the case without a trial.

In granting the request, the judge said the publisher’s disclosures of large chunks of Meghan’s private letter to her father, Thomas Markle, “were manifestly excessive and hence unlawful.”

“There is no prospect that a different judgment would be reached after a trial,” he said.

Meghan’s lawyers said the “deeply personal” five-page letter was intended to be read by her father alone. Her attorney, Justin Rushbrooke, argued in January that the publisher had “no real prospect” of winning the case.

“For these outlets, it’s a game,” Meghan said in her statement after the ruling. “For me and so many others, it’s real life, real relationships, and very real sadness. The damage they have done and continue to do runs deep.”

But the defense argued Meghan wrote the letter as part of a media strategy to rebut a negative view conveyed by her father in indiscreet media appearances, and with help from the communications team in the royal couple’s Kensington Palace office.

Thursday’s ruling means Meghan has won her case on privacy and copyright infringement grounds, but the judge said a “limited trial” should be held to decide the “minor” issue of whether Meghan was “the sole author” and lone copyright holder of the letter.

The defense argues that Jason Knauf, Harry and Meghan’s former communications director, was the letter’s co-author. The judge said that argument “cannot be described as convincing, and seems improbable,” but should still be decided at a trial.

Meghan, a former star of the American TV legal drama “Suits,” married Harry, a grandson of Queen Elizabeth II, at Windsor Castle in May 2018. Their son, Archie, was born the following year.

In early 2020, Meghan and Harry announced they were quitting royal duties and moving to North America, citing what they said were the unbearable intrusions and racist attitudes of the British media. They recently bought a house in Santa Barbara, California.

Mark Stephens, a media lawyer with the firm Howard Kennedy in London, cautioned that the legal saga might be far from over.

“The Mail on Sunday almost have to take it to appeal because the state of privacy laws (are) in a mess in this country, and they need a definitive statement,” he said. “So (Meghan) may not be allowed to walk off the pitch. She may have to go through an appeal yet. So this is just round one.”