Prince William, Meghan Markle, Prince Harry
Prince Harry and Meghan Markle should get enough sleep before their wedding, something Prince William wasn't able to do. Pictured: Princes William, Harry, Markle attend an Anzac Day service at Westminster Abbey on Apr. 25, 2018 in London, England. Getty Images/Eddie Mulholland - WPA Pool

Prince Harry needs to avoid the same mistake that Prince William committed on the night of his wedding day in 2011.

At that time, the Duke of Cambridge revealed that he did not get enough sleep before his big day.

“They were singing and cheering all night long, so the excitement of that, the nervousness of me and everyone singing – I slept for about half an hour,” he said.

Prince Harry, who is expected to stay at Windsor on the night of his wedding day, should get plenty of sleep before he ties the knot with Meghan Markle on May 19. Details about where Prince Harry and Markle will stay will reportedly be revealed on May 18, but it will be close to their wedding venue.

In related news, Prince Harry and Markle will welcome thousands of guests to their wedding next week. Prior to this, royal experts revealed some of the rules that attendees should follow at events as huge as a royal nuptials.

Duncan Larcome, a former royal editor, told Cosmopolitan UK that none of the guests are allowed to post any updates on social media. All mobile devices should also be put away the minute Queen Elizabeth II enters the venue.

“A royal wedding is the only time that the Queen isn’t the last person to walk into a room – she has to wait for the bride. Once the Queen is there, guests will be on their best behavior. Things like tweeting will be an absolute no-no,” he said.

At the royal wedding reception, guests are not also allowed to share any pictures online.

“Guests will be told not to take pictures at any part of the day, particularly during the evening reception at Frogmore House. No pictures ever emerged from William and Kate’s party – anyone who broke this rule would certainly end up in hot water with the happy couple,” Larcome added.

It is also required that all guests stick to the designated seating plan. No changes will be made unless otherwise stated by the palace. Markle’s parents, family, and friends will sit on the left side of the wedding venue.

Guests who will see the Queen should not approach her first. But if she reaches out to anyone, the guest should curtsy before her, says Larcome.