All Smiles: King Charles Attends Easter Service in First Major Public Appearance Since Cancer Diagnosis

King Charles has made his first major public appearance since being diagnosed with cancer in February, RadarOnline.com has learned.

He and Queen Camilla attended Easter services at Windsor Castle on Sunday, greeting and shaking hands with well-wishers outside St. George's Chapel.

Charles, 75, smiled and joked with members of the public after the service. "You're very brave to stand out here in the cold," he told the crowd that had gathered outside the church.

When one person told him to "get well soon," he responded, "I'm doing my best!"

"Keep going strong, Your Majesty. Keep going strong, never give in," another said, prompting Charles to quip, "I have to obey my instructions."

Anne Daley, 65, from Cardiff, held up a Welsh flag when the King arrived and was the first to speak to him after the service.

"Did you see the smile he gave me? He pointed at my flag," she told the BBC. "He had a lovely smile. He looked well. I think he was happy that we've all come."

Charles and Camilla attended the service alongside Prince Andrew and his ex-wife Sarah Ferguson, Princess Anne, and Prince Edward.

Per his doctors' advice, the King and Queen were seated apart from the rest of the royal family to minimize the risk of infection as he undergoes treatment.

They also skipped the reception after the service.

Kate Middleton, Prince William, and their children Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5, were notably absent as they spent the holiday weekend privately at home.

The Princess of Wales revealed last Friday that she was receiving "preventative chemotherapy" after she too was diagnosed with cancer following her abdominal surgery in January.

"We hope that you will understand that, as a family, we now need some time, space, and privacy while I complete my treatment," she said in a heartfelt video message.

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As RadarOnline.com previously reported, Charles and Kate have continued to support each other as they deal with their respective health issues.

When both royals were at the London Clinic, where the king was being treated for an enlarged prostate and the Princess of Wales underwent abdominal surgery in January, Charles was seen "toddling" down the hospital hallway in a robe to visit his daughter-in-law.

"When they were in hospital together there was a lot of toddling down the corridor to spend time with her. He has been encouraging and supporting her throughout," an insider told The Times of London.

"The King has always had a close, warm and unique relationship with the princess. She has a great love and respect for him and his position," the source added.