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LONDON, ENGLAND - MAY 27:  Queen Elizabeth II proceeds through the Royal Gallery before the State Opening of Parliament in the House of Lords at the Palace of Westminster on May 27, 2015 in London, England. (Photo by Suzanne Plunkett /WPA Pool/Getty Images)

In a rare television interview, Britain’s Queen Elizabeth II has shared private thoughts about her coronation, describing one of the crowns she wore at the ceremony as so heavy “your neck would break off.”

Elizabeth, then 27, was crowned amid huge fanfare on June 2, 1953 – a little over year after her father, King George VI, died of lung cancer.

In the hour-long documentary for the BBC, Britain’s longest-reigning monarch spoke openly of the auspicious occasion 65 years ago, describing how the Imperial State Crown is adorned with diamonds and other precious stones making it “very heavy.”

“Fortunately my father and I have about the same sort of shaped head. But once you’ve put it on it stays, I mean it just remains itself,” The Queen said in the BBC documentary.

“You can’t look down to read the speech, you have to take the speech up. Because if you did your neck would break, it would fall off. So there are some disadvantages to crowns, but otherwise they’re quite important things,” she said.

The Imperial State Crown, which she still uses at some formal events, was one of two used during the ceremony; the other being the St. Edward’s Crown, which weighs 4 pounds and 12 ounces and is made of solid gold. She has never worn it since.

The 91-year-old sovereign also revealed how “horrible” it was to travel in the ornate golden carriage to the ceremony at London’s Westminster Abbey – the setting for every coronation since 1066.

“It’s not meant for traveling in at all. I mean it’s only sprung on leather. Not very comfortable. It can only go at walking pace. The horses couldn’t possibly go any faster. It’s so heavy,” the Queen said.

Once there, things didn’t get any easier as the during the ceremony Queen struggled with her dress which was embroidered silk with pearls, gold and silver threads.

“I remember one moment when I was going against the pile of the carpet and I couldn’t move at all,” she said.

Related: The Life of Queen Elizabeth II

However, reflecting on the event, the Queen recalled her father’s coronation – which she attended as a child.

“It’s the sort of, I suppose, the beginning of one’s life really as a sovereign,” she said. “It is sort of a pageant of chivalry and old-fashioned way of doing things really. I’ve seen one coronation and been the recipient in the other, which is pretty remarkable.”

The documentary “The Coronation” is part of the Royal Collection Season and will be screened in the UK on BBC One at 8pm local time on Sunday.