Classical geographers give conflicting views of the ethnic description of the above-mentioned peoples. Ptolemy says that the Astures extended along the central area of current Asturias, between the Navia and Sella rivers, fixing the latter river as the boundary with the Cantabrian territory. However, other geographers placed the frontier between the Astures and the Cantabri further to the east: Julius Honorius stated in his Cosmographia that the springs of the river Ebro were located in the land of the Astures (sub asturibus). In any case, ethnic borders in the Cantabrian Mountains were not so important after that time, as the clan divisions that permeated the pre-Roman societies of all the peoples of Northern Iberia faded under similar political administrative culture imposed on them by the Romans.