Will you be sitting down to watch a new chapter in British history dawn at 3pm on Christmas Day? Because that's when the King delivers his first televised festive message to the nation.

But, warns a leading academic at the University of Kent, don't expect to see him break with tradition as he makes his debut.

King Charles is reported to have filmed the monarch's annual address to the nation and Commonwealth just days before Netflix broadcast the first instalment of its controversial documentary by the Duke and Duchess of Sussex. It is, however, a strictly guarded secret until it is broadcast.

And following the death of Queen Elizabeth II in September, millions are expected to tune in to watch the address - and keep an eagle eye out on which members of his family, if any, are featured in photographs in the background.

"I think his first message will be about him setting a certain tone in line with what was established by his mother," says Dr Emma Hanna, senior lecturer in British history at the university.

"There is always a lot of focus on which family members get the prime spots on camera. I'm sure the grandchildren will.

"I'm not sure the word Netflix will feature that much either due to The Crown or the recent documentary by Harry and Meghan. It will be interesting to see if there's a picture of them in pride of place.

"As with all families, Christmas is a very tricky time and I think there's no trickier family discussion than those the Windsors are having at the moment.

"I think he will talk in very general terms. The general policy of the royal family is never explain, never complain. I think he will probably be advised to stay on that course."

Queen Elizabeth II delivered the final of her 69 televised Christmas messages last year. Viewed by 7.4million viewers on BBC1, it was the channel's biggest audience of the day - beating the Strictly Come Dancing Christmas special into second place. By the time figures from other broadcasters was factored in, the total audience for the Queen's finale was in excess of nine million.

"I think there's still a place for the annual message," adds Dr Hanna. "If there's one time of year when tradition is all, it's Christmas. So I think we will see it continue for the time being. It's very much part of our culture and relationship with the royal family."

But will King Charles resist the urge to talk about some of the topics which he had spoken about before ascending to the throne?

Dr Hanna thinks so. She added: "This is the year where he isn't going to be allowed to speak on causes as much as he was allowed to as the Prince of Wales.

"A lot of the causes close to his heart - such as the environment, sustainability, farming, he may well want to put in some of that, but I think he'll look to approach it more generally - about the war in Ukraine, the importance of the Commonwealth.

"I'm not sure to what extent he would discuss controversial issues."

The monarch's Christmas broadcasts began on BBC radio in 1932 by George V. By utilising the BBC World Service, it was seen as the perfect platform to speak to those nations historically linked in Great Britain.

That first speech was penned by Rudyard Kipling and was, says Dr Hanna "all about connecting to Britain, the homeland, with the British Empire and the Commonwealth".

"I think they thought everyone had had enough of the royal family in 1969..."

The Queen, who broadcast her first in 1952, 10 months after the death of her father, George VI, missed only one year - 1969.

Explains Dr Hanna; "The royal family had broadcast a documentary that year and also Prince Charles had been invested as the Prince of Wales so I think they thought everyone had had enough of the royal family in 1969."

She, instead, issued a written statement.

Filmed by the BBC until 1996, it was then rotated with ITV with Sky News joining the rota in 2011. Sky filmed the address in 3D in 2012 to mark the Diamond Jubilee.

The King's speech will be broadcast at 3pm on BBC1, ITV1 and Sky News.