King Charles rehearses for his coronation in an unprecedented moment in a new BBC documentary about his first year as monarch

A smiling King Charles is seen rehearsing for his coronation in a recording of an unprecedented new BBC documentary charting his first year as king.

The never-before-seen moment – ​​when His Majesty’s suit can be seen peeking out from under his robes as he sits on The Coronation Chair in Westminster Abbey – comes from Charles III: The Coronation Year, a new 90-minute documentary for BBC One that must be one of the highlights of the Christmas program.

The production team was given behind-the-scenes privilege during key moments of Charles and Camilla’s first year in office in and around Buckingham Palace.

A royal aide said permission was given to capture a “historic moment for both the nation and the royal family.”

“It’s a beautiful film and we hope it will illustrate the complexities that went into the coronation itself, and show people a little of the hard work that goes into a change of government,” she added.

The production team was given behind-the-scenes access during key moments in Charles and Camilla’s first year of rule

It is believed to include ‘important’ interviews with friends of Queen Camilla, as well as a ‘moving’ interview with the King’s sister, Princess Anne.

The film, narrated by Helena Bonham Carter and written and co-produced by The Mail’s Robert Hardman, will be broadcast in December as part of the BBC’s Christmas offering.

The broadcaster said yesterday that it contains ‘unparalleled insights from many of those involved, as well as moments of great poignancy and humour’.

Simon Young, BBC Head of History, Factual Commissioning, said: ‘At the heart of this story is a man taking on the job that has always been waiting for him.

‘Everyone wants to know how to take on that challenge. This film provides a behind-the-scenes look at the King and his coronation like never before seen.”