The tradition of cutting cakes can be traced back to the ancient Roman tradition of the groom breaking a cake made of wheat or barley above the bride's head. The ancient Romans believed that this act would bring the couple good luck. Just like in contemporary weddings, ancient Roman couples also ate the crumbs of the bread that was broken together in a ceremony called "confarreatio."
Still in parallel to modern wedding cake-cutting traditions where slices of the cake are given to the guests, crumbs that were left from breaking the cake over the bride's head were collected by wedding guests for good luck. Later on during the time of Lucretius, a Roman poet and philosopher, sweet wheat cakes were crumbled above the bride's head instead of being broken.
The tradition of breaking the wedding cake was believed to have been brought to Britain by the Romans who invaded the lands in 43 A.D. The earliest wedding cakes in Britain were made from simple stacks of spiced buns that were piled as high as possible, and the groom and the bride kissed above it. From spicy buns, the wedding cakes evolved to bride's pye (pie) with a recipe for it mentioned in "The Accomplisht Cook" by Robert May, which was published in 1685. From there the cake evolved into the bride's cake in the 1800s, which was the predecessor of the modern wedding cake.