The weddings of Queen Elizabeth to Prince Philip, Prince Charles and Diana, and Will and Kate
Credit: From left: Gamme-Keystone/Getty Images; Hulton Archives/Getty Images; Chris Jackson/Getty Images

In just a few short months Meghan Markle will walk down the aisle at St George's Chapel in Windsor Castle, which was originally built in the early 13th century — a traditional location, to say the least.

While the couple will get to make a few decisions about their big day, like which dress the bride wears, who walks her down the aisle, and what's on the menu at their reception, little else will be left up to them. In fact, most of their wedding is already predetermined thanks to royal tradition.

The Outfits

As The Standard explained, while Meghan will be able to pick her dress, Harry will have to wear his military uniform, a tradition that dates back to Prince Albert’s wedding.

The one traditional item we can likely expect to see Meghan rocking on her wedding day is a tiara. According to HuffPost, Kate Middleton proudly wore a Cartier Halo tiara from the Queen’s personal collection for her big day. It’s likely Her Majesty will loan one to Meghan as well.

The Reception Arrival

The royal wedding is nothing if not a grand expression of pomp and circumstance, and that means arriving by royal carriage. Like Princess Diana and Prince Charles, Kate Middleton and Prince William, and the Queen and Prince Phillip before them, Meghan and Harry will likely leave the church in a horse-drawn carriage after the ceremony. It will almost certainly be a State Landau, a 1902 gilded open carriage, to be specific. And we can’t wait.

The Wedding Party

While it’s not royal tradition to have a best man or maid of honor, you will likely see both Prince George and Princess Charlotte play a part. Not only is it royal tradition to have flower children and ring bearers, but we also highly doubt the royal family would deny the world these two adorable kids during the biggest royal event of the year.

The Seating Chart

If it follows tradition, the wedding will also be very split down the middle. For example, the royals will sit on the right side of the church, something they always do at weddings, while Meghan’s family and friends will sit on the left.

The Food

The couple will also have two cakes for the reception, and this tradition simply comes down to opulence. They have two cakes because they are royal and they can. Oh, and one has to be a fruit cake. Because that’s what royals like.

The Portrait

After each royal wedding, the entire Windsor family comes together for one amazing portrait. And Harry and Meghan’s wedding may have one more exciting addition in theirs: William and Kate’s new baby. Their wedding will take place mere weeks after Middleton is expected to give birth so perhaps they will bring along the tot for one photo before handing him or her off to a nanny so they can cut a rug at the reception.

The Bouquet

Meghan's wedding bouquet will undoubtedly be beautiful, but it also comes with a special significance. Not only will it include Myrtle, a flower that symbolizes good luck in love and has been in every royal bouquet since Queen Victoria, but she will also leave it at the tomb of the unknown soldier as a sign of respect.