The Spinal Tap Easter Egg You Never Noticed In The Princess Bride

If you're now wondering whether the presence of Reiner's hat in both This Is Spinal Tap and The Princess Bride implies the films share some sort of shared cinematic universe, it appears the director had no real intention of connecting them via that hat. As such, all of you "The Grandson's dad is Marty DiBergi" conspiracy theorists can go ahead and lay that little beauty to rest. 

It turns out Reiner actually had far more practical reasons to drop that USS Ooral Sea hat into frame on The Princess Bride: Because it was the only way he could convince Mark Knopfler to compose the score for the film.

As the Reiner related in the audio commentary on on The Princess Bride's special edition DVD, he met the Dire Straits frontman some time after This Is Spinal Tap was released, and Knopfler was quite the fan of the film. When Reiner set out to helm The Princess Bride, he approached Knopfler to pen the score. Knopfler was keen on the idea, but would only agree to compose for The Princess Bride if Reiner would find a spot in the film for a This Is Spinal Tap reference.

Though Knopfler would later claim the request as a joke, Reiner actually agreed to the arrangement. Unfortunately, he'd lost track of the infamous cap after wrapping This Is Spinal Tap. Sans the actual item, the director had to have it recreated by his props team for its big moment in The Princess Bride. 

Nonetheless, Reiner got it done, and got the great Mark Knopfler to make some seriously beautiful music for what many consider to be the most perfect, if surprisingly adult-themed, fantastical romantic comedy ever produced.