King Charles and Queen Camilla drove to the long late morning service at St George’s Chapel in Windsor Castle, west of London.
The 75-year-old, wearing a suit and light blue tie, smiled and waved to the people who had waited for hours to see him before he went into the chapel.
After the service, Charles and Camilla greeted some of the supporters outside, shaking hands and briefly chatting with some of them.
Attending the yearly religious ceremony is a well-established tradition for the royals, with other family members present on Sunday.
However, Prince William and Catherine were notably absent this year, as Catherine is receiving treatment following her recent cancer diagnosis.
This situation is an unprecedented crisis for the monarchy, as two of its most senior members are simultaneously battling serious illness.
Charles was only 17 months into his long-awaited reign when Buckingham Palace announced in early February that he had cancer and would be pausing all public engagements as he started treatment.
He had undergone surgery for a non-cancerous prostate condition in January but was later diagnosed with a different cancer. The specific type of cancer has not been disclosed.
The king has been continuing with behind-the-scenes work, holding some in-person meetings, and increasingly attending official events.
This week, he released a pre-recorded Easter audio message — broadcast in his absence at a Maundy Thursday service in Worcester Cathedral, central England — emphasizing the importance of acts of friendship.
The monarch was also photographed meeting community and faith leaders at Buckingham Palace in central London on Tuesday.
Meanwhile, last week, photos showed him meeting diplomats at the palace, as well as veterans of the Korean War, at two separate events.
Charles stated earlier this month that he would continue to serve “to the best of my ability” and he had been “deeply touched” by people’s wishes for his health.
He commended Catherine for her bravery in a video message last week, as she announced that she was undergoing chemotherapy.
She was last seen at a public event on December 25, then had abdominal surgery in January, after which cancer was detected.
Her Kensington Palace office stated at the time that she was not expected to be ready to return to public duties until after Easter.
AFP