The Duchess of Cornwall said Black Beauty was her favourite book during her “pony-mad” youth and it still makes her emotional, as she highlighted the importance of reading to children.

Camilla revealed her father, Major Bruce Shand, would often narrate stories to her and her siblings during their younger years, a time when she “thought of little else” apart from horses.

She named Anna Sewell’s bestselling novel, about a well-bred horse sold to cruel owners, as the first book which “stuck in her mind” as a child.

Speaking to Lord Dobbs as part of his Christmas guest editorship of BBC Radio 4’s Today Programme, she said: “In those days I was a sort of pony-mad child, and I thought of very little else apart from horses and ponies and charging about on them, so I think Black Beauty was the first book that stuck in my mind.

“I can see it now – there was Ginger. Every time I think about poor old Ginger with his head hanging out of the cart with his tongue hanging, it makes me cry now, and I think that was possibly one of my favourites.”

She said her other favourite books as a child were The Scarlet Pimpernel, a story about an Englishman who rescues aristocrats during the French Revolution before they are sent to the guillotine.

Camilla said: “Another book that my father used to read to us all the time because he loved a bit of adventure, was The Scarlet Pimpernel, and he became this great hero in all our eyes and I loved all the adventures.”

The duchess revealed she bought a number of books as Christmas presents for her five grandchildren, two girls and three boys.

One granddaughter was given Philip Pullman’s La Belle Sauvage while twin brothers Gus and Louis, the sons of her daughter Laura Lopes, were given Dracula and Lord Of The Rings.

Camilla said: “If you learn to read, however difficult your life is at the time, you can pick up a book and you can escape.

“You can laugh, you can cry, it just takes you out of the real world and it gives you a different dimension to life.”

Camilla is patron of a number of literacy charities and recently launched the Duchess of Cornwall’s Reading Room on Instagram for book lovers of all ages and abilities.

The Prince of Wales, Camilla’s husband, also appears in the programme reciting an extract from Charles Dickens’s A Christmas Carol.

Elsewhere, Lord Dobbs asks listeners to learn more about prostate cancer, having been diagnosed himself earlier this year.

Raheem Sterling, General Sir Nick Carter, Dr Jane Goodall, James Rebanks, Mina Smallman and Jacky Wright will all take turns guest-editing the Today Programme this week.