There are generalized elements of the campaign's historical background that can only be categorized as Precursor history. This includes the Age of Poisoned Sea and Sky and its immediate aftermath.
Humans before the Cataclysm
Enigmatic travellers with an interest in human civilization
Cataclysm's Aftermath
Luddite sentiment gone amok
The current stage of human history
The end of all that was, the beginning of all that is