The Neanderthals were a subspecies of early humans that lived in Europe and western Asia from around 400,000 to 40,000 years ago. They were well-adapted to cold environments and predominantly carnivorous. While shorter than modern humans, Neanderthals had larger brains and more robust bodies. They made tools, controlled fire, built shelters, hunted in groups, and showed early signs of cultural development. The last Neanderthals are believed to have gone extinct around 25,000 years ago, possibly due to competition with modern humans, violent climate change, or interbreeding when Homo sapiens moved into their habitats.