In past years,Prince Charles and Camillacelebrated their anniversary on Instagram.

“Thank you for all the well wishes on Their Royal Highnesses' 15th wedding anniversary!”

acommemorative postfrom 2020 reads.

Prince Charles smiling

This year, however, the pair joined therest of the royal familyin remembering Prince Philip.

ManyPrincess Dianafans scorned the couple when they announced their engagement.

Simmons also claimed that Camilla once called Diana “that mad cow.”

Prince Charles and his family

Other fans of theroyal familydid accept the marriage.

Indeed, based on reports from the couple themselves, the 16-year marriage has been a successful one.

By all accounts, the couple will continue to serve the Crown for years to come.

Camilla walking with Prince Philip

However, it’s widely known that Philip had a close relationship with Princess Diana.

The duke even tried to help save themarriage between Charles and Dianabefore their divorce.

Philip believed it was “silly to risk everything with Camilla.”

Prince Charles saluting with Philip

But in recent years, it was reported that Philip and Camilla’s relationship had improved.

Camilla even made an official statement in regards toPhilip’s healthat the beginning of March (viaUSA Today).