Between 400,000 and 40,000 years ago, Neanderthals (Homo neanderthalensis), a near relative of modern humans (Homo sapiens), inhabited Europe, sections of western Asia, and the Middle East. They resembled modern humans in many ways, including tool use, hunting techniques, and social structures, but they were also stockier, stronger, and had greater brow ridges and a distinctively shaped skull. Neanderthals had sophisticated habits including making art, burying their dead, and maybe speaking. They were also incredibly adaptive, surviving ice ages and a variety of environmental conditions.

Research on the extinction of Neanderthals, which happened about 40,000 years ago, is still ongoing, although a number of causes most certainly had a role in their demise. Competition with Homo sapiens, who migrated into Neanderthal areas at the same time, is one of the main theories. Given their superior tool technology, social structure, and capacity for adaptation, modern humans may have gradually surpassed Neanderthals in the competition for scarce resources. Given that Neanderthals were primarily dependent on frigid, Ice Age habitats, climatic change may also have played a role. They may have been forced into smaller, isolated communities as their traditional hunting areas and prey may have diminished due to the warming environment.