Isu Era

The Isu Era was a period of time marked by the existence of the First Civilization as the dominant species on the planet. It was during this era that the Human-First Civilization War took place.

Juno, a scientist of the First Civilization, was born in Feyan City, in the year 2195 of the Isu Era. The Toba Catastrophe took place in the year 2306 of the Isu Era - roughly 75000 BCE.

Reference

 * Assassin's Creed: Syndicate – World War I simulation