My players and I are starting a new campaign soon, with brand new characters set in the same world and after all of our previous campaigns. In the first session, I plan on having them run into some cultists that the players (but not the characters) have encountered in a previous campaign. One of the new characters was a student of one of the old characters, and it is mentioned in their backstory that "he showed me a museum of his previous adventures." Would a History check be used to determine if this new character identifies the cultists from the museum?
More generally, what's the time limit on a History check? Can they roll a history check to see if they remember things from the previous session? From their backstory? Or is it explicitly past events they did not experience? If this is the case, then what sort of check would I use for more recent history, like a "memory" check? Straight Wisdom, Investigation, straight Intelligence, Perception?