What's the old dude from Pawn stars doing there?

Explanation: Pope Leo I met with Attila the Hun in an attempt to convince him not to march on the city of Rome itself after Attila penetrated into Italy. Bizarrely, he succeeded. The details of the negotiations are disputed, but Pope Leo must've had a helluva gilded tongue.

On Sleipnir no less!

That hat screams "This is totally a regular hat and not some kind of bladed throwing hat, I promise!"

Imma need a whole lot of context for this picture.