According to some anti-diffusionistic (or evolutionistic, or “immobilistic”) models, the European Neolithic originated from local innovations. However, indications accumulated during the past years prove that a large part of the cultural traits of the oldest Neolithic of the Balkans have an apparent correlation with Anatolia. These correlations can clearly be seen at the site of Kovačevo in Bulgaria which yielded especially rich information about architecture, techniques and forms of bone industry, body ornaments, “pintaderas,” figurines and certain characteristics of pottery, including some clearly imported objects. Other sites in northern Greece and Bulgaria support these observations. One can therefore suggest a chronological model with five principle periods of the Neolithic colonization of the Balkans. Nevertheless, the reasons motivating Anatolian populations to colonize Europe remain to be explored, although the Neolithic remained relatively stable in the zone of its origin, the Levant, during all of the “Pre-Pottery Neolithic.” With the revival of deterministic models, which partially derives from modern ecological fear of “global warming,” a climatic deterioration has been invoked for the end of the 7th millennium (the “8.2k cal BP climatic event”). One could, however, also put forward political and cultural reasons: The refusal to live in large settlements with a dense concentration of people, a system collapsing in the Near East at exactly this point in time. This chapter aims to explore these different tracks.