In his "Commentarii de Bello Gallico", Caesar describes how two tribes, the Tencteri and Usipetes, had been driven from their traditional lands by the Germanic Suebi, whose military dominance had led to constant warfare and neglect of agriculture. This original homeland of the two tribes is not clear but by the time of Caesar the Suebi had settled in a very large wooded area to the east of the Ubii, who at this time lived on the east bank of the Rhine, on the opposite bank from where Cologne is today. It has been argued that the Tencteri and Usipetes specifically may have come from the area of the Weser river to the east of the Sigambri, because it is near to where the two tribes appeared on the Rhine, and Caesar reports the Suevi in this area. It would also explain the apparently friendly relations of the Tencteri and Usipetes with the Sigambri, who might have been their traditional neighbours. (In later Roman times this area inhabited by Caesar's Suebi was inhabited by the Chatti.)