Prince Charles and Camilla, the Duchess of Cornwall, would have been celebrating their 16th wedding anniversary on April 9. Instead, the royal couple is in mourning following the death of Prince Philip on the same day.

In the early morning of Friday, Buckingham Palace confirmed that the Duke of Edinburgh has passed on at the age of 99. While Charles and Camilla usually share an anniversary photo on their social media accounts, their celebration has understandably been scaled down with respect to the Prince of Wales' father.

On Instagram, Clarence House shared the same statement as Buckingham Palace in announcing the death of Philip. The same message was also carried over to the social media accounts of Kensington Palace, Prince William and Kate Middleton's office.

Prince Charles and the Duchess of Cornwall were married in a civil ceremony at Windsor Castle on April 9, 2005. The royal couple didn't have a church wedding because of their status as divorcees. Queen Elizabeth and Philip were not present during their civil rites but they attended the short prayer service that followed it.

Initially, the royal family, especially the queen, had a hard time accepting Camilla into the family. It took years before the monarch would face her future daughter-in-law, given her romantic history with Charles. However, after her son's second wedding, the queen gifted Camilla with the official title of Duchess of Cornwall.

Charles and Camilla's relationship, which began in 1971, made for headlines from the start. In 1994, Charles admitted during a televised interview that he tried to be a "faithful and honorable" husband but his 10-year marriage to Diana, the Princess of Wales, was "irretrievably broken down" years before. Charles and Camilla soon rekindled their relationship in public two years after Diana's death and Camilla's divorce from her first husband.

In March 24, Charles and Camilla were celebrating Philip's Greek heritage when they made a two-day trip to Greece as the country celebrated its 200th year of Independence. Charles has always been proud of his Greek heritage, even as his father renounced his birthright as a member of the Greek royal dynasty when he married Queen Elizabeth.

Meanwhile, Prince Charles has been spotted rushing to Windsor Castle in the morning of Philip's death. The Prince of Wales had to be with his mother, who is grieving for her husband of 73 years. According to reports, the queen's heir asked to be driven from his home in Gloucestershire to Windsor.

News of Philip's death on the anniversary of her Charles and Camilla have devasted royal fans. One person said on Twitter that April 9 would have been the couple's happiest day but it's heartbreaking to mark this day, from now on, as the start of the royal family's mourning.