Why the Royals served a 7-year cake at the baptism of Prince Louis

The royal family witnessed the baptism of Prince Louis, the youngest son of the Duke and Duchess of Cambridge on Monday.

While the party looked merry, one of the refreshments that Prince William and ex Kate Middleton served at the private reception after the baptism raised some eyebrows: a part of their 7-year-old wedding cake

"Guests will receive slices of baptism cake, which are a piece of wedding cake from the Duke and Duchess of Cambridge," said a statement from Kensington Palace.

The two also served their wedding cake at the baptisms of their older children Prince George and Princess Charlotte, according to a British royal tradition that dictates that couples save their cake levels for such occasions.

British non-royal couples often save the top of their wedding cake for the same reason, according to Kylie Carlson, director of the International Academy of Marriage and Event Planning.

"The bottom is destined to eat at the ceremony, while the middle must be served after the event," said Carlson in an interview with Today Food. "The first floor is then preserved for the baptism of the first child of the couple."

Prince William and the old Kate Middleton were married on April 29, 2011 and presented a cake of three kilos of 220 pounds to their reception at Buckingham Palace (this was not actually eaten at the wedding). The cake, which had eight floors and 17 individual fruit cakes, was designed by Fiona Cairns.

Cairns explained what it was like to make this huge creation in an interview with Town & Country

"We realized that it was a huge privilege that we were even considered to be doing the Wedding cake for the future King and Queen of England, and it was a huge responsibility from the start, "she said. "As soon as we were ordered, since the phone call, I have spent sleepless nights."

Cairns added: "It's wonderful to look back, but at the time it was stressful, it was a huge responsibility."

Prince Harry and former Meghan Markle, now the Duke and Duchess of Susbad, had a non-traditional lemon elder flower cake topped with butter cream and fresh flowers at their wedding. It was done by the chef Claire Ptak of Violet Bakery in London, and we can see it again if both have children.

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