Prince Harry’s marathon quest against Britain’s tabloids produced a “monumental victory” in the courts, he said in a TV interview that will air Thursday, but it was a “central piece” of the bitter rift between him and other members of the British royal family.

Speaking for the first time since winning hundreds of thousands of pounds in damages from Mirror Group Newspapers over his claims that it had wrongfully invaded his privacy, Harry, 39, said that he had been vindicated by the judge’s ruling, even if the price to his relations with his family was high.

“I’ve made it very clear that this is something that needs to be done,” Harry said in excerpts released by ITV News, part of an hourlong documentary about the phone-hacking scandal. But he added, “It would be nice if we, you know, did it as a family.”

Harry, the younger son of King Charles III, did not explain exactly how his legal battle had further ruptured relations with his father or brother, Prince William. In his memoir, “Spare,” he attributed the rift to multiple causes, including his family’s treatment of his wife, Meghan Markle, a biracial American former actress.

But Harry’s determination to sue the tabloids put the royal family in an awkward position. In his lawsuit against Rupert Murdoch’s News Group Newspapers, Harry disclosed that William had settled claims that the publisher hacked his cellphone for a “huge sum of money.”

The settlement, Harry said, grew out of a “secret agreement,” under which the family deferred legal claims against the publisher to avoid having to testify about embarrassing details from their intercepted voice mail messages.