The 'Lion King' cast had to follow these royal protocol rules before greeting Prince Harry and Meghan Markle

While Beyoncé might be American royalty, the "Lion King" cast still had to follow protocol upon meeting Prince Harry and Duchess Meghan Markle.

Disney's "Lion King" held its European premiere in London on Sunday, where Harry and Meghan walked their first red carpet as a couple. The star-studded movie cast, including Beyoncé, Seth Rogen, Billy Eichner and more, were all in attendance as they awaited the royal couple.

SEE ALSO: When Meghan Markle met Beyoncé at the 'Lion King' premiere

“You’re given a lot of protocol to follow which is unusual,” Rogen revealed during a recent appearance on UK’s This Morning. “Respect their personal space. They’re the only people I’ve met who come with protocol so that was interesting. And then I think what we were trying to gauge is how many people were following the protocol and how strict the protocol is.”

“I assume you get put in the Tower Of London if it all goes wrong. I’ve got to think of the repercussions. I’d like to come back here one day,” he added.

Eichner, who plays Timon in the live action film, explained, "like Seth said, they tell you you’re supposed to say your Royal Highness, you can’t speak until your hands are locked together in a handshake and all these crazy things, and I didn’t know how much you were supposed to follow that so I started panicking. We were watching what our friend Keegan [Keegan-Michael Key] did and he did none of the protocol either and just kind of nodded his head, then it all fell apart.”

The "Billy on the Street" host took to his Instagram to share a video of his nerves upon meeting the royals.

"Caught on video last night completely freaking out to @sethrogen about how to greet Prince Harry and Meghan," he captioned the clip.

During the premiere, Duchess Meghan was reportedly overheard telling Pharrell, who produced several songs for "The Lion King," that royal life isn't 'easy.'