Queen Elizabeth Broke Protocol In a Surprising Way at Prince William and Kate Middleton's Wedding

As Prince William and Kate Middleton celebrate their 13th wedding anniversary, fans are looking back on an accidental faux pas the late queen made at the ceremony.

Apparently, royal etiquette dictates that women should get out of the car on the curb side, not the street side. But Queen Elizabeth and Prince Philip's car pulled up on the wrong side of the street, so Her late Majesty had to slide across the seat to get out.

"The Queen got out on the wrong side and there was a bit of a fluster," etiquette expert Alexandra Messervy said on the A Right Royal podcast (via Us Weekly). "The correct protocol for her was to be on the curb side, and she was on the reverse side."

Messervy explained that the etiquette protocol stems from when royals rode in horse-drawn carriages and women had to "avoid the mud." Of course, most royal watchers never noticed the supposed faux pas, and instead focused on William and Kate's love story.

Royal etiquette aside, though, William and Kate are supporting each other more than ever, 13 years after they tied the knot. Kate announced her cancer diagnosis in March, and she's been staying out of the public eye. Former BBC royal correspondent Jennie Bond told The Sun that "William has never been more protective of his wife and children as now," with everything the family is going through.