What region was Ciel Phantomhive the Earl of?
Earls, Dukes, and Counts can all vaguely be considered the same thing. All of them could either be rulers over a section of the Queen's territory ("Earl Peter Raeves of Wessex") or it was just a title for a part of the hierarchy that was close to the monarch. I think he's called the Earl of Phantomhive, or I suppose you could say Earl Phantomhive, because that puts him in his spot in the hierarchy and as the head of the Phantomhive family. Please correct me if I'm wrong but that's how I always understood it.