Kate Middleton breaks tradition during emotional royal appearance

Onlookers of this weekend's Remembrance Sunday clocked onto the Princess of Wales breaking some long-standing protocol during the sombre service.

For those unable to tune in, a number of senior royals flocked to the Cenotaph in Whitehall, London, on Sunday (9 Oct) to commemorate the 80th anniversary of the end of the Second World War, as well as the lives lost in all British conflicts.

The televised service saw King Charles III lead a two-minute silence at 11 a.m., before going on to lay a wreath, designed to pay tribute to his grandfather, King George VI, upon the area's war memorial.

A wreath was also laid down on Queen Camilla's behalf, as she looked on from the balcony of the Foreign, Commonwealth and Development Office.

There, she stood alongside Prince Edward and Sophie, Duchess of Edinburgh, the Duke and Duchess of Gloucester, and Kate.

Kate stood on the balcony alongside Queen Camilla for the Remembrance Sunday service over the weekend (Mark Cuthbert/UK Press via Getty Images)

As we say, however, the eagle eyes of several observers picked up on the latter, who appeared deeply sorrowful during the service, supposedly straying away from a major royal tradition.

During previous wartime commemorations, Princess Kate has been seen wearing three poppies as a sign of respect to those no longer with us.

This year, however, the Princess surprised onlookers by opting to attach a singular floral pin to her black coat.

Kate's break from tradition might have gone unnoticed if Camilla hadn't been sporting a trio of poppies on her coat just inches away.

Royal experts previously theorised that the mother-of-three's preference might have been based upon the number of family members each royal lost during the Great Wars, with Kate's great-grandmother having lost three brothers in action during WWI.

In 2018, she famously viewed letters from these lost ancestors during an emotional visit to the Imperial War Museum. Interestingly, though, this theory was never confirmed by a Palace representative.

In previous years, Kate has worn three poppies (Max Mumby/Indigo/Getty Images)

Others theorised, meanwhile, that a collection of poppies appeared much more visible than just one, so that Kate could never be accused of failing to pay her respects appropriately, Hello! Magazine reports.

This may also have been why the late Queen Elizabeth II always wore five poppies while attending the special service, which were thought to memorialise each wartime service - the Army, the Navy, the RAF, the Civil Defence, and women.

Again, however, this theory was never confirmed by officials.

On Saturday (8 November), Kate also attended the Royal British Legion Festival of Remembrance at the Royal Albert Hall, along with her eldest child, Prince George, whose attendance caused some excitement online.