Well Dumbledore says OotP that :'It was against my inclination to allow the subject of Divination to continue' implying that it was already taught.
Whether any of the Marauders would have chosen it as one of their subjects, though, is an entirely different matter.



rereading!) that when Dumbledore interviewed professor Trelawney (1980? I think it was somewhere between 1979 and '80) he mentioned something about removing Divination from Hogwarts' curriculum but since he had known Trelawney's great grandmother, who was an actual Seer, he had decided he should see Telawney to be polite. Then she made the prophecy so he decided to keep her close.So I think the subject was taught before he actually saw Trelawney.

All of you are so majorly great!

