as one of five major Kulturkreise or "culture-groups" whose dialects developed in the southern German area from the first century BC through to the fourth century AD. Apart from his own linguistic work with modern dialects, he also referred to the archaeological and literary analysis of Germanic tribes done earlier by Gustaf Kossinna In terms of these proposed ancient dialects, the Vandals, Goths and Burgundians are generally referred to as members of the Eastern Germanic group, distinct from the Elbe Germanic. Tribes names in classical sources Northern bank of the Danube In the time of Caesar, southern Germany had a mixture of Celtic and Germanic tribes and was increasingly coming under pressure from Germanic groups led by the Suebi. As described later by Tacitus, what is today southern Germany between the Danube, the Main, and the Rhine had been deserted by the departure of two large Celtic nations, the Helvetii in modern Schwaben and the Boii further east near the Hercynian forest. In addition, also near the Hercynian forest Caesar believed that the Celtic Tectosages had once lived. All of these peoples had for the most part moved by the time of Tacitus. Nevertheless, Cassius Dio wrote that the Suebi, who dwelt across the Rhine, were called Celts. Although, this may follow a Greek tradition of labelling all barbarian people north of the alps as Celtic. Strabo (64/63 BC – c. 24 AD), in Book IV (6.9) of his Geography also associates the Suebi with the Hercynian Forest and the south of Germania north of the Danube. He describes a chain of mountains north of the Danube that is like a lower extension of the Alps, possibly the Swabian Alps, and further east the Gabreta Forest, possibly the modern Bohemian forest. In Book VII (1.3) Strabo specifically mentions as Suevic peoples the Marcomanni, who under King Marobodus had moved into the same Hercynian forest as the Coldui (possibly the Quadi), taking over an area called "Boihaemum". This king "took the rulership and acquired, in addition to the peoples aforementioned, the Lugii (a large tribe), the Zumi, the Butones, the Mugilones, the Sibini, and also the Semnones, a large tribe of the Suevi themselves". Some of these tribes were "inside the forest" and some "outside of it". Tacitus confirms the name "Boiemum", saying it was a survival marking the old traditional population of the place, the Celtic Boii, though the population