Charles III turns 75 on Tuesday, showing no sign of a let-up in activity just over a year since he became king of the United Kingdom after the death of his mother Queen Elizabeth II.

Halfway through his eighth decade, the British head of state is due to spend the day carrying out public engagements followed by a private dinner at his London residence, reports Gulf News.

The visit will see him officially launch the Coronation Food Project, an initiative aimed at tackling food poverty by redistributing food that would otherwise end up in landfill.    

King Charles will also host a reception at Buckingham Palace for 400 nurses and midwives as part of this year's 75th anniversary celebrations for the state-run National Health Service (NHS).

Queen Camilla, 76, once revealed that the famously workaholic king is particularly hard to buy gifts for.

"I will tell you that he is the most difficult person in the world to buy a present for... So he likes to make a list of things that he wants so you get it exactly right," she said on the occasion of her husband’s birthday.

Bd-pratidin English/Golam Rosul