In many ways they are typically childlike etchings, but perhaps the smart attire gives it away.
Drawings that the King did of his parents Elizabeth II and the Duke of Edinburgh, when he was five or six, are to go on sale after being unearthed after more than 40 years.
The crayon and pencil sketches show both in grand clothes, with the late Queen wearing a striped gown, a purple tiara and red earrings, and Prince Philip in a dinner suit and bow tie.
The sketches, titled “Mummy” and “Papa”, were produced by a young Charles around 1953-55.
They are expected to fetch between £5,000 to £10,000 when they go under the hammer at Hansons Auctioneers in Etwall, Derbyshire, on June 16.
The drawings form part of an “extraordinary” royal memorabilia collection which includes 10 early drawings by the King as well as letters, family photographs, Christmas cards and a 1937 Buckingham Palace manuscript menu diary.
It was largely amassed between the 1950s and 1970s by author, journalist and former royal correspondent Henry Ramsay Maule.
Mr Maule, from Reading, wrote several books and worked as British correspondent at the New York Daily News for 21 years.
He also wrote, under a pseudonym, All The Queen’s Children about Elizabeth II’s offspring.
He was a friend of royal photographer Marcus Adams and enjoyed a long working friendship with members of the Royal Household.
Mr Maule also gained Palace approval to write a biography of Prince Philip and was in the process of collating information for the book, with the help of a long-standing royal servant, when he died in 1981.
The items given to him to assist with his work were inherited by his family and are now being sold on.
Charles Hanson, owner of Hansons Auctioneers, said: “This is an extraordinarily touching collection.
“These poignant childhood drawings and emotive photos remind us that away from the pomp, pageantry and demands of serving the nation, our royals treasure the ordinary, everyday moments of family life.
“Given a crayon and pencil, nearly every child’s first drawings depict their family. Our King was no different.
“This collection will help people relate to him even more in his role as our monarch.”
Other early drawings by the King that will be up for sale include a pair of carmine bee-eater birds, signed “Charles”, a delivery van in Harrod’s-style livery stating “Happybright, Mr Charles’s Shop” and a picture of a rabbit, owl, deer and squirrels.
A cartoon illustration made by Charles for his father, depicts a master sailor receiving a tot of “Hair Restorer” from an urn labelled “Lilac Flavour” and comes with a note, dated March 25, 1954 reading: “Dear Papa, I am longing to see you in the ship, Love from Charles.”
Handmade cards by a young Princess Anne for her father, featuring a yacht, house and balloons, are also set for auction and estimated at £300 to £600.
The King has gone on to become a keen artist, his watercolour landscapes earning high praise from critics.