For the ancient Thessaliens, a myth permitted them to account for the genesis of the Thessalian plain, of its fertility which was well-known to the Greeks, and of a particular feast, probably the harvest feast, in which all the inhabitants of the region participated. The interest accorded to this myth today, as in late antiquity, lies in its three elements and in the legendary Pelasgians, who are the principal actors of the story. One must meanwhile go farther in the analysis, establishing that the myth presents a very explicit organisation in the chronology of events: in an « original » time the creation of a space of which the revelation is given to the first occupants, the Pelasgians, by a divine messenger, then the taking possession of ...