The Diplomatic Corps Reception is arguably the most highly anticipated annual event on the royal calendar. The white-tie affair is one of the few times during the year the ladies in the family don the spectacular royal jewels — and Queen Camilla sparkled in the late Queen Elizabeth II’s rarely seen Aquamarine Ribbon Tiara

The Princess of Wales made a bold statement in the color to honor the flag of Qatar while hosting Sheikh Tamim bin Hamad Al Thani on his royal visit.

As Buckingham Palace confirms Camilla was suffering from a form of pneumonia, the Waleses step up to kick off the state visit.