While several celebrities such as Naomi Cambell, Kate Moss and Demi Moore, attended Princess Eugenie's royal wedding, George and Amal Clooney were among the big name celebrity no-shows.

On Friday morning, Eugenie, who is ninth in line to the throne, married tequila executive, Jack Brooksbank. Brooksbank works as a brand ambassador for the high-brow Casamigos Tequila brand which is owned by Clooney. The now-husband of Princess Eugenie told the Daily Mail days before the wedding that he and his bride planned on serving the fancy tequila at their wedding but he could not confirm if Clooney and his wife would attend the ceremony.

"I'm in charge of drinks and we'll be serving Casamigos," he said.

It was speculated that Clooney and his wife, who live in London with their twins, would have attended the royal wedding since they had also attended Prince Harry and Meghan Markle's in May. But when it came time for Friday's royal celebration, the Clooney couple was not among the A-list crowd who showed.

According to E! News, the actor's human rights attorney wife was tied up at a women's conference speaking egagement in Pennsylvania. The event may serve as the reason why the couple was unable to attend the wedding.

Apart from the "Ocean's 12" actor, singer's Ed Sheeran and Elton John were also not in attendance. It was rumoured that both were invited but could not attend due to tour schedules in the United States.

And while the majority of the royal family came out to celebrate Eugenie and Brooksbank's big day, there was one other family member who was noticeably absent.

Camilla, Duchess of Cornwall and Rothesay, and wife of Prince Charles, did not attend the morning wedding at Windsor Castle.

A rep from Clarence House confirmed to Fox News earlier this week the 71-year-old would not be attending the wedding but refused to provide further details.

However, Clarence House tweeted Thursday Camilla was in Scotland visiting Alford Community Campus to meet schoolchildren who use the center. The campus offers facilities to the local community, including a library, a theater and a dance studio.

The palace added Camilla participated in art and cooking classes with the children.

Other celebrities who attended the event included Cara Delevingne, Liv Tyler and Ellie Goulding.

Fox News' Stephanie Nolasco contributed to this report.