There is, or was, a comparative history option in the Oxford history syllabus, but I (and ISTR also Ladyofastolat) did the historiography option instead so I don't know what it in it.

My impression was that it involved a lot of sitting round going 'Oooh! Cultures! How different they are! How similar they are!' like a bunch of hippies smoking a sort of historical joint. Though that may just have been the tutor that taught it at SHC.