The artist who designed the first coins of the King to go into circulation was inspired by a collection of change his mother had kept from her childhood.

Martin Jennings worked painstakingly for a year, alongside experts at the Royal Mint, to create the portrait of Charles on the front of the new coins.

He used images taken to mark the now King’s 70th birthday in 2018 for the portrait, before choosing the typeface and layout of the inscription with designers at the official coin maker in Llantrisant, south Wales.

Mr Jenning’s initials, MJ, feature in tiny letters by the King’s neck on the coin.

He told the PA news agency he used images of previous Kings – who traditionally appear uncrowned – when designing Charles’ portrait.

“I was inspired by effigies of George VI and Edward VIII from the 1930s,” Mr Jennings said.

“My mother gave me a little sack of coins which she had collected as a child and I looked at those.

“There were these lovely big old pennies with the king of them. I love to think of them rattling through people’s pockets before the Second World War.

“Each of those coins represents a purchase and a transfer, it makes me wonder how many stories are attached to each coin.”

Mr Jennings said he worked in “close collaboration” with experts at the Royal Mint to create Charles’ portrait on the front of the coins.

He described seeing them in person at the Royal Mint site as “astonishing”, with so much work and skill distilled into a small coin that would be reproduced millions of times.

The artist officially started production of 50 pence coins, in memory of Queen Elizabeth II, at the Royal Mint’s site on Thursday.

A total of 9.6 million of the coins will be initially struck. They will begin appearing in the public’s change from December.