Prince Philip’s health once overshadowed a royal celebration.

In December 2011, the Duke of Edinburgh was forced to stay in the hospital after receiving treatment for a blocked coronary artery. For the first time, the 97-year-old senior royal missed the family’s traditional Christmas service at Sandringham as he was still recovering.

The 2012 documentary "Kate and William: The First Year" recalled how Prince Philip’s illness “overshadowed” the royal family’s Christmas celebration. According to royal correspondent Victoria Arbiter, the members of the royal family and the public gathered together to support Queen Elizabeth II.

“The Queen had 27 house guests at Sandringham. The whole family was there which was fantastic,” she said.

“It wasn’t just the family that turned up, so did the crowds,” Arbiter added.

Veteran royal photographer Arthur Edwards also noticed a huge difference during that year. Prince Philip was missing, but the number of people who showed up to see the royals was so much more than the previous years.

“I have done Sandringham Church for at least 20 years and I know about crowds,” Edwards said. “I have been there in snow, in gales, in torrential rain, and when the sun's been shining but last year [2011] the crowd was the biggest I have ever seen.”

Last year, Prince Philip also didn’t join the rest of the royal family for the annual event. On Christmas Day, the royal family, including Prince Charles, Camilla Parker Bowles, Prince William, Kate Middleton, Prince Harry and Meghan Markle, gathered together for the morning service. It was the first time that the fab four had been seen together after their rumored rift.

Middleton and Markle were very friendly. The two duchesses were photographed laughing and chatting as they walked to the church with their respective husbands. On the other hand, Prince William and Prince Harry looked distant and ill-at-ease.

According to Daily Mail royal correspondent Rebecca English, there was nothing to worry about the duke’s health, even if he skipped the outing. Prince Philip was reportedly in Sandringham and was not sick. He just wanted to spend the day with his family privately.

Prince Philip usually stays in Sandringham with Queen Elizabeth II after the holidays, and they only return to the palace after Feb. 6 because it’s the monarch’s father’s death anniversary.

Prince Philip
Prince Philip raises his hat in his role as Captain General, Royal Marines, makes his final individual public engagement as he attends a parade to mark the finale of the 1664 Global Challenge, on the Buckingham Palace Forecourt on August 2, 2017 in London. Getty Images/Yui Mok