>>56696805Ruins of Alph predates Celestica settling in Sinnoh. The celesticans came from Sinjoh, and the Sinjoh people are the ones who made the Ruins of Alph.
I can't remember off the top of my head if Unova's ancient history can be squeezed anywhere chronologically.
PLA wasn't even that far back in the past considering we know the history of humanity dates back well over 3k years.