Grey's Anatomy and Station 19. Friends and Mad About You. Brooklyn Nine-Nine and New Girl. Petticoat Junction and Green Acres. Pretty much all of the Marvel universe. Cinematic crossovers are common practice. But The Crown and Outlander? Now that's a crossover that calls for celebration in the era of Peak TV.

While watching The Crown Season 4, Outlander fans' ears may have perked up at the mention of "Sandringham." Unfortunately, the Royal Family wasn't speaking of the Duke of Sandringham. But no matter, because it was glorious to hear Outlander and The Crown star Tobias Menzies utter the name "Sandringham" again.

The very intentional-not-coincidental-at-all crossover occurs in Episode 2 of The Crown Season 4, "The Balmoral Test." Menzies' Prince Philip surprises the visiting Diana Spencer for an early morning stalk of the injured stag on the Queen Elizabeth II's Scottish property. As he gently interrogates the future Princess Diana, he wonders if he's ever encountered the young woman before. "So I suppose I must have seen you growing up on the estate at Sandringham when you lived in the cottage there," Menzies says in his best received pronunciation (RP) accent (or something like it). And thus, a crossover was born!

The Sandringham House is the private home of Queen Elizabeth II, located in Norfolk on the Sandringham Estate. As the Sandringham Estate's website notes, Park House on the estate was Princess Diana's childhood home.