King Charles III quietly marked a special occasion.

On Sunday, the 75-year-old royal attended church service near Balmoral Castle with his wife, Queen Camilla. The king was spotted driving his wife on the grounds of Crathie Kirk. The pair didn’t exit the vehicle to speak to onlookers, but they did smile and wave to members of the public.

Sunday’s service fell on the day that the late Queen Elizabeth II would have marked her 98th birthday. Elizabeth, who was the longest reigning monarch in British royal history, died on Sept. 8, 2022. She was 96.

The outing comes three weeks after Charles and Camilla attended Easter Sunday service at  St. George’s Chapel at Windsor Castle. Easter service marked the first time that Charles appeared in full public capacity after scaling back his royal duties following the news of his cancer diagnosis.

In a move that shocked well-wishers, Charles did a walkabout, greeting members of the public who lined up to see the family.

Missing from the outing was Charles’ son, Prince William and his wife, Kate Middleton. The couple spent the Easter holiday out of the public eye with their three children as Kate undergoes preventative chemotherapy following her own cancer diagnosis.

Since revealing his health news, Charles has been resting and recuperating from his cancer treatments at Sandringham Estate until he is fully cleared to go back to work. In recent weeks, however, he has been picking his work back up and taking meetings and other state business from Buckingham Palace.

In March, Peter Phillips opened up about his uncle’s recovery, saying the British monarch was feeling “frustrated” over his recuperation timeline and pushing himself and those around him to speed up the progress.

“He’s in good spirits,” Phillips told Sky News Australia. “I think, ultimately, he’s hugely frustrated. He’s frustrated that he can’t get on and do everything that he wants to be able to do.”

He continued, “He is always pushing his staff and everybody and his doctors and nurses to be able to say, ‘Actually come on, you know, can I do this? Can I do that?'”

Phillips added: “But he is very pragmatic [and] he understands that there’s a period of time that he really needs to focus on himself.”

Despite his cancer battle, Charles has been there to offer support to Kate. In March, royal expert, Katie Nicholl told ET that the monarch put his full support behind his daughter-in-law’s choice to reveal her cancer diagnosis with the world.

“My understanding is that the king was really behind her doing that video message even though it was a bit of a breach of protocol, just a bit of a departure for the norm, because he recognizes how important that connection with the public is,” Nicholl said. “He’s also been on the receiving end of that support from the public, and that has [helped] him through a very difficult period.”

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