That's why, when Prince Harry and Meghan Markle announced their engagement in November 2017, many royal watchers started the countdown on what Beatrice and Eugenie would be wearing atop their heads on May 19.
Now - the moment has finally arrived.
The pair have opted for a more toned down look, sporting headbands rather than show-stopping fascinators.
Beatrice and Eugenie regularly make headlines for their fashion choices - most notably the duo frequently appear at royal events in headpieces that range from the fabulous to the wacky.
Take a look at some of their best below.