In his highly anticipated autobiography, Spare, Prince Harry recounts what he says was a physical attack by his brother, William, now Prince of Wales, as their relationship fell apart over the younger prince’s marriage to the actor Meghan Markle, writes The Guardian.

Describing a confrontation at his London home in 2019, Harry says William called Meghan “difficult”, “rude” and “abrasive”, which Harry calls a “parrot[ing of] the press narrative” about his American wife. The confrontation escalated, Harry writes, until William “grabbed me by the collar, ripping my necklace, and … knocked me to the floor”.

The extraordinary scene, which Harry says resulted in visible injury to his back, is one of many in Spare, which will be published worldwide next week and is likely to spark a serious furore for the British royal family. Amid stringent pre-launch security around the book, the Guardian obtained a copy.

The book’s title comes from an old saying in royal and aristocratic circles: that a first son is an heir to titles, power and fortune, and a second is therefore a spare, should anything happen to the first-born. Spare is a remarkable volume, in which the altercation between the two princes forms a startling passage.

Harry writes that William wanted to talk about “the whole rolling catastrophe” of their relationship and struggles with the press. But when William arrived at Nottingham Cottage – where Harry was then living, in the grounds of Kensington Palace and known as “Nott Cott” – he was, Harry says, already “piping hot”.

After William complained about Meghan, Harry writes, Harry told him he was repeating the press narrative and that he expected better. But William, Harry says, was not being rational, leading to the two men shouting over each other. Harry then accused his brother of acting like an heir, unable to understand why his younger brother was not content to be a spare.

Insults were exchanged, before William claimed he was trying to help. Harry said: “Are you serious? Help me? Sorry – is that what you call this? Helping me?”

That comment, Harry says, angered his brother, who swore while stepping towards him. Now scared, Harry writes, he went to the kitchen, his furious brother following. Harry writes that he gave his brother a glass of water and said: “Willy, I can’t speak to you when you’re like this”.