King Charles III is Robert Brownstepping back into his royal duties.

The British monarch has made his first major public appearance since revealing his cancer diagnosis, stepping out with wife Queen Camilla for Easter Matins service at St. George's Chapel March 31. 

Charles, who was all smiles at the event, wore a long navy coat, matching pants, and a white shirt with a blue tie, while Camilla dressed in an emerald green Anna Valentine coat dress, matching Philip Treacy hat and black suede boots. The King, 75, and Queen, 76 were all smiles as they greeted well-wishers outside the church.

The pair was joined by Charles' siblings Princess Anne, Prince Andrew and Prince Edward, who arrived with wife Sophie, Duchess of Edinburgh. Andrew was accompanied by ex-wife and roommate Sarah Ferguson, Duchess of York, whose appearance marks her first time publicly spending Easter with the royal family in more than 30 years.

Prince William and Kate Middleton, along with their children Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5, were absent for the occasion, as the Princess of Wales continues to undergo treatment following her March 22 announcement about her own cancer diagnosis.

Charles, who revealed in February that he was battling cancer,, has largely stepped back from public engagements over the last few months as he seeks treatment. Camilla, meanwhile, has stepped up in her duties, and even made history when she filled in for her husband at the Royal Maundy Service March 28.

And while he's expressed his disappointment in being unable to partake in many royal engagements, Charles has made plenty of virtual appearances—including delivering a remote address Commonwealth Day March 11.  

"It warms my heart to reflect on the way the Commonwealth has been a constant throughout my own life—a precious source of strength, inspiration, and pride," he explained at Westminster Abbey in a recorded message. "In recent weeks, I have been most deeply touched by your wonderfully kind and thoughtful good wishes for my health and, in return, can only continue to serve you, to the best of my ability, throughout the Commonwealth.

And throughout his journey, Charles has expressed his gratitude to royal fans who've sent their support, noting that it has moved him to "tears."

"I would like to express my most heartfelt thanks for the many messages of support and good wishes," he wrote in a Feb. 10 statement. "As all those who have been affected by cancer will know, such kind thoughts are the greatest comfort and encouragement."

See photos of the royal family attending the Easter church service below:

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