Being a purist and a huge fan of Elder Scrolls too, I have to point it out: Morrowind was ES III, where as ES IV was Oblivion 😃
Damnit. XD I wasn't sure, but my mental process was 'no, Oblivion must have been V because they could do the phase transition to have the V appear as part of the title!'... which is also true for IV. I'll go fix that.