Neanderthals: they were our cousins
The common ancestor between humans and Neanderthals lived around 500,000 years ago. Our ancestors separated from them long before Homo sapiens appeared in Africa.
It is interesting that Neanderthals were much bigger and much stronger than us, and their brains had a much larger volume than ours. Still, they disappeared and we became a very successful species.
Though is there is much speculation, up to now no one knows for sure the reason Neanderthals went extinct.