Queen's health deteriorated over King Charles safety: 'Tense moment'

A latest revelation has uncovered new details about the royal family's serious fears over King Charles' safety.

The late monarch, Queen Elizabeth II, reportedly went through a difficult situation to protect her eldest son, then-Prince Charles.

She was reportedly close to a 'nervous breakdown' over fears for Charles.

It's a decades-old story when Prince Charles' lavish and extravagant investiture was planned to be the first televised ceremony of its kind in colour in 1969 at Caernarfon Castle in north-west Wales.

But with civil unrest in Northern Ireland accelerating at an alarming pace, a Welsh separatist group targeted the location.

Explosives had been planted and gone off in and around the area. Two men, Alwyn Jones, 22, and George Taylor, 37, were killed after a bomb they had placed on railway tracks near the event detonated prematurely.

Speaking on the Daily Mail's YouTube channel, Hardman described how the event had been planned to be a "coronation mark two".

"It was a very tense moment. Only a few months later, the trouble started again in Northern Ireland," he explained.

"It was all over the world really - you just had the assassination of Martin Luther King and Bobby Kennedy in America. People were really nervous, worried about the direction the world was heading in."

Hardman says the situation had left the late Queen really worried that something was going to happen.

"The Queen had always taken the view that if something happened to her, she'd live with it - die with it," he explained.

"It went with the territory. But this was the threat of terrorism against her son, his event and the family. Afterwards, Charles went off on a tour of Wales. The Queen went back to London to bed, cancelling all engagements for the week. Very, very unlike her."

"She was meant to be going to the Wimbledon Finals, had various garden parties, things to do. The whole lot was cancelled."

Officially, the Palace had said she was suffering from the flu - though the royal biographer, quoting an anonymous source, cast doubt on this.

"Someone very close to her team told me that it wasn't flu, it was nervous exhaustion.

"I don't think you could call it a full nervous breakdown, because she was back on duty just over a week later - but it was the nearest thing to a nervous breakdown."