Prince Harry has claimed he saw "this red mist" in his brother Prince William during their alleged altercation in 2019.

In his upcoming autobiography Spare, the British royal claimed his older brother physically attacked him during a dispute about Harry's wife Meghan, Duchess of Sussex inside of his London home, Nottingham Cottage.

Discussing the alleged incident in an interview with ITV News presenter Tom Bradby, Harry recalled how he saw a red mist - or extreme anger which clouds one's judgement - descend upon his sibling.

"What was different here was this level of frustration," Harry claimed in a preview clip released on Friday. "I talk about the red mist that I had for so many years, and I saw this red mist in him... He wanted me to hit him back. But I chose not to."

In the book, the 38-year-old alleged he suffered "scrapes and bruises" on his back after William knocked him to the floor and he landed on a dog bowl.

"It all happened so fast. So very fast. He grabbed me by the collar, ripping my necklace, and he knocked me to the floor. I landed on the dog's bowl, which cracked under my back, the pieces cutting into me. I lay there for a moment, dazed, then got to my feet and told him to get out," he wrote in the memoir.

Elsewhere in the preview clip, the host noted all the references to drug use in the book and told Harry the revelations will "surprise people" and the royal insisted, "But (it's) important to acknowledge."

The Duke of Sussex also told Bradby that he ultimately wants to reconcile with his family.

"First, there needs to be some accountability," he said. "The truth, supposedly, at the moment, has been there's only one side to this story, right? But, there's two sides to every story."

Harry's 90-minute interview will air in the U.K. on Sunday, two days before Spare is released.

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