The one thing most brides do that Princess Eugenie is strictly not allowed at her wedding.

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It happens so regularly it’s pretty much expected: the bride runs late to her wedding.

Whether it’s to make the groom nervous or to give tardy guests a few extra minutes to get to their seats, most brides will start walking down the aisle later than the invitation says.

But Princess Eugenie can’t make a delayed entrance on her wedding day (which happens to be today) – she must arrive exactly on time. And it’s all because of her grandmother, the Queen.

Some royals are rulebreakers. Here are just a few. Post continues.

As Queen Elizabeth’s former press spokesperson Dickie Arbiter told The Sun: “The Queen doesn’t do late.”

The Queen, he explained, is always on time, unless unforeseen circumstances hold her up.

“If she has to be late somewhere it will be for a very good reason, that there’s a breakdown somewhere or she’s stuck in traffic,” Dickie said.

Out of respect to their family’s head, the Queen’s children and grandchildren don’t arrive late either.

Which is why Princess Eugenie is scheduled to arrive at St George’s Chapel at exactly 10.55am before she walks down the aisle at 11am (9pm Australian east coast time) on Friday.

Her husband-to-be Jack Brooksbank will be there waiting, having arrived at 10.15am, The Sun reports.

After the ceremony, the couple will trot around the streets of Windsor in a carriage before heading to the Queen’s home for a champagne reception and later on to their own private reception.

It’s a very similar schedule to Prince Harry and Meghan Markle’s wedding in May.

We’re hoping that Princess Eugenie also makes the most of her big day, fashion-wise, with a second dress for her reception.

The Duchess of Sussex swapped her Givenchy wedding gown for a sophisticated Stella McCartney creation for her reception.