THE GREAT GALLIC LEAGUE

The study of the Gallo-Roman ways requires the measurement of the distances between cities and the determination of the units used. The universality of the Roman mile is supplemented by a specificvalue in Gaule, the league. The official relationship between these sizes is described by the texts: two leagues are worth three miles.Such is the doctrines prevailing in the majority of the works devoted to this subject.

The localization of the intermediate stations, starting from the tables and routes, implies many cartographic measurements, and it is there that a surprising observation is essential: conversions do not tally with geographical reality. Other methods give long series of leagues appreciably larger than the commonly allowed value. It is during our work of localization of sites discovered by air archaeology in Poitou-Charentes that these divergences became completely obvious.

This difference in length (10% approximately) is too significant due to errors and the high number of measurements, associated with different sources, to be excluded any risk from isolated accident. There exists formally, on certain routes of Aquitaine (studied area), metric based on one league purely indigenous, most probably former to the conquest : the great Gallic league. It is not a new discovery, others noted it before us, but their opinion was never retained and the great treaties of reference do not make mention of it. We present testimonys of the omnipresence of this indigenous league on the studied routes, wishing to contribute, by a different approach, with the recognition of this fundamental unit.