3 Billion Years Ago
This was a very long time ago. Imagine going back in time before Hitler launched the First Missile, before DaVinci drew his first Masterpiece, in fact, let's skip further before Man even existed (Which was 2 Million Years ago BTW). Oh yeah, there were the Dinosaurs! Don't mind them they were here only 65 Million Years ago. I'm talking about a time when Charnia (500 Million Years ago) haven't even existed yet.
Before all those, there were only simple microscopic single cells. They first appeared around 3 Billion BC where the Earth wasn't the same as what we know right now. In fact, they were the most advanced form of life on the planet. And that's way over half the entire history of life on earth.