WATCH | Would you pay R15k for a decades-old slice of royal wedding cake?

Prince Harry and Meghan Markle's wedding is fast approaching. But if you can't make it to Windsor Castle on May 19, fear not, you can still indulge in a slice of royal wedding history.

Cake slices from five royal weddings, including those of Prince Charles and Princess Diana, and Prince William and Kate Middleton, will be going under the hammer.

The slices of cake, which come in either boxes or tins, will be sold by auction house Julien's from as little as R3,700 to as high as R15,000.

A slice from Charles and Diana’s wedding, presented in a white box with “CD Buckingham Palace 29th July 1981” in silver printing and wrapped in a paper doily, is estimated to fetch between R9,800 to R15,000, the auction house said.

The fruit cake made for Prince William and Kate Middleton’s 2011 wedding is pegged to sell for about R7,400 to R9,800. Julien’s sold a slice of William and Kate’s cake for about R92,600 in 2014.

Other cake slices include Charles’ 2005 wedding to Camilla Parker Bowles and Prince Andrew and Sarah Ferguson’s 1986 nuptials, which each are estimated to fetch R7,400 to R9,800.

WATCH | Slices of royal wedding cakes to be auctioned off 

But if you're already planning a high tea with your friends while watching a re-run of the royal wedding, be warned. The slices of cake are not edible.

“These come from people who attended the wedding and kept them in the freezer the entire time,” Julien's CEO Darren Julien said of all the cake slices, adding they have not been preserved by other means.

The royal wedding cake slices will be auctioned on June 23 in Las Vegas.

• Additional reporting by staff reporter.