MINOR QUIBBLE — Duke of Earl

I've been watching some of The Tudors recently — Netflix is now streaming all 4 seasons — and all this talk about kings, dukes, and earls made me think of the 1962 Gene Chandler hit, "Duke of Earl." Did the writers of this song just randomly throw together two feudal titles to create the refrain? A duke is one guy, an earl is another. Why would there be a Duke of Earl? That's like calling someone "King of Prince" or "President of Secretary." Makes no sense. Oh, and don't watch the following video unless you're OK with "Duke of Earl" being stuck in your head for the next 49 years (if it isn't already).

(Does the crowd seem strangely morose and serious in this video? Perhaps that whole duke-and-earl issue was gnawing at them as well...)