History recognises the expansion of the Celts from inland and central Europe southward, westward and eastward, but is silent about any expansion northward. No one doubts that in these early times the parts of Europe northward of the old Celtic country already described were occupied by the Germans, but Greek and Latin writings have no word of the Germans until the last quarter of the third century B.C. Yet we know from archæology that there was trade intercourse long before that time between the Mediterranean countries and the shores of the Baltic, extending even to Scandinavia. As geographical facts, the Baltic and Scandinavia were known to the Greeks, if only vaguely known to them, in the time of Eratosthenes, _i.e._, about 200 B.C. How is it, then, that the Germans are not mentioned by that name or by any name? I suggest that the reason was that the Germans of that period were so much under Celtic domination that they were not recognised as a distinct people of importance. The first mention of Germans in history is found in the Roman Acta Triumphalia for the year 222 B.C., in the record of the battle of Clastidium. Clastidium, now called Casteggio, is in northern Italy, on the south side of the river Po and a few miles from that river. It is a little west of the meridian of Milan, which at the time of the battle was Mediolanum, the chief town of the Insubrian Gauls. In the battle, the Roman consul Marcellus overcame the Insubrians and gained the _spolia opima_ by slaying with his own hand their commander Virdumarus. The Acta Triumphalia state that he triumphed "over the Insubrian Gauls and the Germans." Now so far as is known or thought probable there was no German population at the time settled anywhere within hundreds of miles of Clastidium, whereas the Insubrian Gauls were settled on the spot or in its near neighbourhood. Moreover, unless the Germans were there fighting in considerable force, it is most unlikely that any notice of them would have appeared in the record. The commander was a Gaul, bearing an undoubted Celtic name. Therefore the Germans at Clastidium were not fighting for their own hand, they had not come there as invaders. Thus we are brought to the interesting conclusion that, on this first appearance of the Germans in history, they had been brought from their own country, hundreds of miles away, to assist a Celtic people resident in the valley of the Po. To assist them in what capacity? Undoubtedly either as hired troops or as forces levied on a subject territory. Whichever view we take, the presence of German forces at the battle of Clastidium in 222 B.C. must be regarded as an indication that the German people, or portion of them, were still at that time under Celtic predominance. I say "still at that time," because it will be seen that the Celtic ascendancy over the Germans soon afterwards came to an end.