The royal who won't be at Princess Eugenie's wedding

Princess Eugenie will marry Jack Brooksbank at Windsor Castle on Friday. Photo / Getty Images

The royal family will be out in force on Friday to see Princess Eugenie exchange vows.

The ninth in line to the British throne, 28, is set to marry her long-term boyfriend Jack Brooksbank in St George's Chapel at Windsor Castle, watched by her grandmother the Queen and cousins Princes William and Harry - not to mention myriad celebrity guests.

But one key royal who won't be among the congregation is the Duchess of Cornwall, who is understood to be skipping the ceremony due to a prior commitment in Scotland, reports the Daily Mail.

According to Hello! Prince Charles will attend his niece's wedding without his wife Camilla, because it clashes with her long-standing engagement to visit a school.

Royal commentator Victoria Arbiter said Camilla's absence from proceedings "doesn't indicate any malice or ill-feeling".

She tweeted: "Royals don't like to disappoint. Given she'd already committed to attending a school event it's duty first."

FEMAIL has contacted Clarence House for comment.

Camilla is likely to be the only senior royal not in attendance on Friday, with the Queen and the Duke of Edinburgh and the Cambridge family set to make an appearance at their second royal wedding in less than six months.

Prince George and Princess Charlotte are rumoured to be taking on pageboy and flower girl duties for the ceremony, after being part of the adorable pint-sized bridal party that followed Meghan down the aisle on May 19th.

There is said to be no bad blood between the pair. Photo / Getty Images

Eugenie's sister Princess Beatrice, 30, is expected to be maid of honour.

Further details of Eugenie and Jack's big day have emerged as it draws near, with the world-famous Italian opera singer Andrea Bocelli set to perform at the ceremony.

Meanwhile costume designer turned bespoke baker Sophie Cabot has been tasked with creating the couple's wedding cake - an autumn-inspired red velvet and chocolate affair decorated with ivy, likely a nod to Eugenie and Jack's home, Ivy Cottage in the grounds of Kensington Palace.

Royal fans are eagerly awaiting their first glimpse of the Princess' wedding dress on Friday, as the bride has kept details of the designer under wraps.

She has confirmed only that she has chosen a "British-based" designer, prompting odds to be slashed on Erdem, a label she and other members of the royal family have long favoured for occasion wear.