The Limes (meaning frontier or limit in Latin) was the Roman name for the border between the Roman Empire and the territories of the several "barbarian" clans of Germany and Northern Europe. The Limes extended from Koblenz on the Rhine to Eining on the Danube. Its total length was 568km, it included at least 60 castles, 900 watchtowers and some (mainly trading) towns. The Limes was formed by the connection of the Upper Germanic Limes along the Rhine and the Rhaetian Limes along the Danube, building a common borderline during the reign of Augustus (Octavian). Germanic invasions in the late 3rd century led to the abandonment of the Limes.