The earliest events relevant to a Pathfinder 1st ed campaign.

[Joynt Jezebel]

I want to know what is the oldest relevant historical event that anyone has ever come
across in a Pathfinder 1st ed, campaign.

I will be running a one shot, and hopefully later a campaign, that I expect will smash all records in this respect. I want to see if this is so.

[marcryser]

I ran a game which saw the PCs journeying back into (Alternate) Earth's dim past to prevent a group of serpent cultists from disrupting the asteroid strike that caused the extinction of the dinosaurs.

[Joynt Jezebel]

That is a very cool idea. If the time of the C/T boundary, when the dinosaurs who were not birds died out, that puts it 65 million years. A long time.

I go much older, more than 13.8 billion years. Which should suggest something to the science nerds.