Homo neanderthalensis is a human species, commonly called Neanderthals. They first arose in Europe, and later spread from Europe to parts of Africa and the Middle East. Tribes of Neanderthals worked their way across Siberia, competing with Cro-Magnon tribes in the south. Eventually, Neanderthals crossed over the Bering Strait into North America, followed by Cro-Magnon. Some competed with the Ndutu in South America as well.
Neanderthals were stronger and larger than humans, with slightly larger and more advanced brains as well. However, they had a smaller range of sounds they could produce, crippling their language. This gave them difficulties in creating a united civilization, which gave them a disadvantage when competing with the Cro-Magnon.