The royal family love their tiaras, and a wedding look wouldn't be complete without one. Kate Middleton's Cartier wedding tiara was an important heirloom, while Meghan Markle also borrowed hers from the Queen.
But while Meghan and Kate are allowed to pimp their gowns with the accessory as much as they like, Princess Eugenie isn't officially allowed to - yet.
According to ancient royal protocol, women aren't allowed to wear tiaras during the days, just for an evening do, and they are reserved to married women.
Which is why Princess Eugenie technically can't wear one on her wedding day (and Fergie didn't wear a wedding tiara), however this is likely to be waved as it was for both Kate and Meghan, and in fact any other royal bride.
Etiquette expert Grant Harold told the BBC, 'Flashy diamonds and tiaras are not worn during the day, and only married ladies wear tiaras. For married ladies it was a sign of status and would show you were taken and not looking for a husband.'
He continued, 'For the gentleman it was a clear sign not to make advances toward the lady in question.'
Well if a princess can't wear a tiara on her wedding day, something's not right.
