It seems to me, then, to be certain that the Belgae not only came into Gaul from Germany, but were themselves a mixed population of Celts and Germans speaking a Celtic dialect. Holder assigns their migration into Gaul to the third century B.C. It is, however, undesirable to attempt to fix anything but a somewhat extended period for migratory movements of the kind. The instance of the Helvetii proves that down to Cæsar's time the Celts in contact with the Germans were still in a very mobile condition. Before using the facts hitherto stated and the conclusions derived from them to throw whatever light they can on the Celtic colonisation of Ireland, it may be well to state in a general way what can be said as to the stage of civilisation reached by the continental Celts before their subjugation by the Romans. Some modern writers, but not very recently, have written about a Celtic Empire in ancient Europe. The nearest approach to authority for the existence of such an empire is a statement by Livy, who says: "While the elder Tarquin reigned in Rome, the supremacy among the Celts belonged to the Bituriges. They gave a king to the Celtic land. Ambigatus was his name, a very mighty man in valour and in his private and public resources, under whose rule Gaul was so abounding in men and in the fruits of the earth that it seemed impossible to govern so great a population." The most that can be made of this passage, supposing that Livy had it on better authority than some other parts of his history, is that at one time the Bituriges held what the Greeks called hegemony, a political primacy among the Gauls, and this, too, only in the time of a single king. It may reflect a genuine Celtic tradition, going back to the time when the Celts were still a compact nation inhabiting a relatively small territory. When we come to contemporary evidence of the political condition of the Celts, we find that everywhere on the continent and in Asia Minor, their form of government resembles that of the Roman Republic. There are no kings, and the power of the state is vested in a senate with certain high executive officers. The Celtic form of government in historical time was that of a patrician republic. The Celtic people was divided into a large number of small states without any organised superior power. From time to time, however, one or other of these states might acquire a degree of political pre-eminence over a group of neighbouring states, forming a loose federation in which it took chief direction of the common affairs. We find the same tendency among the states of ancient Greece. In Asia Minor, the three states of the Galatae formed themselves into a strict federation, with a fixed constitution, a common council of state and a common executive both civil and military.