Strabo, Geography
H.C. Hamilton, Esq., W. Falconer, M.A., Ed.

North of the Tagus is Lusitania, the principal of the nations of Iberia, and the one which has most frequently encountered the arms of the Romans. On the southern side this country is bounded by the Tagus, on the west and north by the ocean, on the east by the well-known nations of the Carpetani, the Vettones, the Vaccæi, the Gallicians, and by others not worthy to be mentioned on account of their insignificance and obscurity. On the other hand, certain historians of the present day give the name of Lusitanians to all of these nations.

To the east the Gallicians border on the nation of the Asturians and Keltiberians, the others [border] on the Keltiberians. In length Lusitania is 3000¹ stadia; its breadth, which is comprised between the eastern side and the opposite seacoast, is much less. The eastern part is mountainous and rugged, while the country beyond, as far as the sea, consists entirely of plains, with the exception of a few inconsiderable mountains. On this account Posidonius remarks that Aristotle was not correct in supposing that the ebb and flow of the tide was occasioned by the sea-coast of Iberia and Maurusia.² For Aristotle asserted that the tides of the sea were caused by the extremities of the land being mountainous and rugged, and therefore both receiving the wave violently and also casting it back. Whereas Posidonius truly remarks that they are for the most part low and sandy.