At the end of the Middle Palaeolithic around 40,000 years ago, a population of archaic humans, Neanderthal men descended from the earliest settlers, lived in Europe. They were perfectly adapted to the land and its resources. They and their ancestors had survived all the climate and environmental changes that had occurred throughout the Pleistocene for hundreds of millennia, but they mysteriously disappeared upon the arrival of anatomically modern men, who originated in Africa. The latter were the humans from our own species, Homo sapiens, also called Cro-Magnon men in Europe, and they would gradually replace the archaic populations of the Old World. In Catalonia, archaeology shows how the old civilisation of the Neanderthal men, the Mousterian, which remained in place for many millennia with few changes, was swiftly replaced by another new civilisation which was very different and more dynamic, the Aurignacian, which was a civilisation of modern men. Over time, the Aurignacian evolved to give way to other civilisations of largegame hunters of the European Upper Palaeolithic. In Catalonia, the sites in Serinyà, among others, allow us to study the civilisation of the Neanderthal and Cro-Magnon men near the time of their replacement and to precisely date when this took place. They also provide us with the oldest remains of modern men found in Catalonia