The Ubaid represents a fundamental phase for the emergence of social complexity and is the first cultural phaenomenon
having spread throughout almost the entire Fertile Crescent. A long-lasting debate exists about the
modalities of this expansion, while its chronology – around the last quarter of the sixth millennium BC – is
generally considered as well established. However, recent reassessments of some ancient radiocarbon dates and
ceramic data from the whole Ubaid sphere clearly suggest that the chronology of the emergence of the Ubaid
is as controversial as the modalities of this process. On the basis of new data from northern Mesopotamia and
the northern Levant, this paper focuses on the Halaf-Ubaid Transition, as well as on the contact between the
Ubaid and other cultural entities in Levantine areas generally considered as external to the Ubaid sphere. Technical
and morpho-stylistic analysis of some sixth millennium assemblages seems to suggest that the Ubaid expansion
could have begun much earlier than generally imagined and could have implied very frequent and deep
cultural relations with other Mesopotamian and Levantine cultures
