Queen Camilla opened up for the first time about her harrowing experience being “attacked on a train” as a teenager.

While the royal said on BBC Radio 4’s “Today” show Wednesday that she had “sort of forgotten about” the assault by “somebody [she] didn’t know,” she does “remember … being so angry” afterward.

“I was reading my book, and this boy – man – attacked me, and I did fight back,” the 78-year-old recalled.

“I remember getting off the train and my mother looking at me and saying, ‘Why is your hair standing on end, and why is a button missing from your coat?’” she added.

Camilla noted that she was “so furious about it,” with the emotions “lurking for many years.”

She was inspired to share her story over BBC commentator John Hunt’s wife, Carol, and daughters Louise and Hannah being killed by Louise’s ex-partner.

“When the subject about domestic abuse came up, and suddenly you hear a story like John and Amy’s, it’s something that I feel very strongly about,” Camilla said.

While King Charles III’s wife has not publicly shared her story before, she did speak to then-London mayor Boris Johnson about the incident in 2008.

Johnson’s communications director, Guto Harri, told “Power and Palace” author Valentine Low about Camilla’s “serious conversation” with the politician.

“[She was] the victim of an attempted sexual assault when she was a schoolgirl,” Low wrote in his September release.

“She was on a train going to Paddington — she was about 16, 17 — and some guy was moving his hand further and further,” he added.

When Johnson “asked what happened next,” she allegedly replied, “I did what my mother taught me to. I took off my shoe and whacked him in the nuts with the heel.”

The “self-possessed” teen then “jump[ed] off the train” upon arrival, told a man in uniform about the attack and had him arrested.

In 2008, notably, Camilla and Johnson were discussing opening rape crisis center, with Hari revealing, “Nobody asked why the interest, why the commitment. But that’s what it went back to.”

If you or someone you know is affected by any of the issues raised in this story, call the Sexual Assault Hotline at 1-800-330-0226.