Origination

When: Year 0, the first day
At the beginning, humanoidkind found themselves spontaneously created in a vast world of mountains, grasslands, deserts, and swamps, and surrounded by ocean on most sides. They began with clothing, equipment, and language, and came in a wide variety of races with a mix of features. They quickly built cities and formed societies over the course of the next two centuries. Present day, at the beginning of the campaign, is about 200 years after Origination.
Nobody knows how humanoids were created, or why. Countless theories exist: intelligent design by a higher being, creation by the spirits, widespread amnesia, and rewound time. Some members of longer-lived races have existed since the Origination, but none of them are able to explain how everything began.
A recent theory is that the Origination occurs on a cycle, with new species being created at the beginning of each era and destroyed at the end. It’s unknown how each era begins, but they all end with the Fiends wiping out all humanoid life.