Neanderthals made and used a diverse set of smart tools, controlled fire, lived in shelters, made and wore clothing, were skilled hunters of large animals and also ate plant foods, and occasionally made symbolic or ornamental objects. There is evidence that Neanderthals intentionally buried their dead and occasionally even marked their graves with offerings, such as flowers. No other primates, and no earlier human species, had ever practiced this sophisticated and symbolic behavior.

DNA has been recovered from more than a dozen Neanderthal fossils, all from Europe. We don’t know everything about our early ancestors. But scientists are constantly in the field and the laboratory, excavating new areas and conducting analyses with groundbreaking technology, continually filling in some of the gaps about our understanding of human evolution. 

Both fossil and genetic evidence indicate that Neanderthals and modern humans evolved from a common ancestor between 500,000 and 200,000 years ago. Neanderthals and modern humans belong to the same and inhabited the same geographic areas in Asia for 30,000–50,000 years; genetic evidence indicate while they may have interbred with non-African modern humans, they are separate branches of the human family tree which are separate species.

We learn that Neanderthals and modern humans may have had little direct interaction for tens of thousands of years until during one very cold period, modern humans spread across Europe. Their presence may have prevented Neanderthals from expanding back into areas they once favored and served as a catalyst for the Neanderthal’s impending extinction. Over just a few thousand years after modern humans moved into Europe, Neanderthal numbers diminish to the point of extinction. All traces of Neanderthals disappeared by about 40,000 years ago. The most recently dated Neanderthal fossils come from western Europe, which was likely where the last population of this early human species existed.

http://humanorigins.si.edu/evidence/human-fossils/species/homo-neanderthalensis