King Charles III is celebrating his 76th birthday near the end of a trying year in which he and his daughter-in-law Princess Kate were both diagnosed with cancer.

The British monarch is marking the occasion by opening two food distribution hubs after last year launching the Coronation Food Project in an effort to "bridge the gap between food waste and food need." On Thursday, he is opening the initiative's first two food hubs — distribution centers which are designed to save and circulate surplus food.

Charles visited one of the hubs in London that is hosting a "surplus food festival," making meals created from food which would have gone to waste, and he is virtually opening the other site in northern England.

Their aim is to make it easier for food charities such as FareShare and the Felix Project to provide support for those in need, Buckingham Palace said. The project has helped save the equivalent of more than 2.2 million meal portions since its launch, per the palace.

Charles' birthday is also being marked with gun salutes at the Tower of London and in the capital's parks.

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King Charles attends 'Gladiator 2' premiere, marks birthday amid cancer

The monarch's birthday comes after he attended the premiere of "Gladiator II" in London on Wednesday night, where he greeted director Ridley Scott and stars Denzel Washington, Paul Mescal, and Pedro Pascal. Queen Camilla, who has been recovering from a chest infection, was not in attendance.

King Charles was diagnosed with cancer after a procedure for benign prostate enlargement, he shared in February. He returned to his public duties by the end of April.

Charles' birthday was previously celebrated in June with the yearly Trooping the Colour parade. Princess Kate attended the ceremony, which marked her return to public life after she was diagnosed with cancer.

Princess Kateto host annual Christmas carol service following cancer treatment

In the following months, Kate gradually attended more public events before revealing in September that she has completed chemotherapy. The Princess of Wales is set to host an annual Christmas carol service in London next month.

Princess Katemakes rare public appearance after completing cancer chemo

Speaking recently to British media during a visit to South Africa, Prince William said his year has been "dreadful" amid Charles and Kate's cancer battles.

"It's probably been the hardest year in my life," William said. "So, trying to get through everything else and keep everything on track has been really difficult."

Contributing: Michael Holden, Reuters; Brendan Morrow, USA TODAY