The northern races who were to form part of the currents of mediaeval life are grouped under the names of Celts and Teutons.[144] The chief sections of the former, dwelling in northern Italy and Gaul and Spain, were Latinized and then Christianized long before the mediaeval period, and themselves helped to create the patristic and even the antique side of the mediaeval patrimony. Their rôle was largely mediatorial, and geographically, as well as in their time of receiving Latin culture, they were intermediaries between the classic sources and the Teutons, who also were to drink of these magic draughts, but not so deeply as to be transformed to Latin peoples. The rôle of the Teutons in the mediaeval evolution was to accept Christianity and learn something of the pagan antique, and then to react upon what they had received and change it in their natures.
Central Europe seems to have been the early home alike of Celts and Teutons. Thence successive migratory groups appear to have passed westwardly and southerly. Both races spoke Aryan tongues, and according to the earliest notices of classic writers resembled each other physically--large, blue-eyed, with yellow or tawny hair. The more penetrating accounts of Caesar and Tacitus disclose their distinctive racial traits, which contrast still more clearly in the remains of the early Celtic (Irish) and Teutonic literatures. Whatever were the ethnological affinities between Celt and Teuton, and however imperceptibly these races may have shaded into each other, for example, in northern France and Belgium, their characters were different, and their opposing racial traits have never ceased to display themselves in the literature as well as in the political and social history of western Europe.
The time and manner of the Celtic occupation of Gaul and Spain remain obscure.[145] It took place long before the turmoils of the second century B.C., when the Teutonic tribes began to assert themselves, probably in the north of the present Germany, and to press south-westwardly upon Celtic neighbours on both sides of the Rhine. Some of them pushed on towards lands held by the Belgae, and then passed southward toward Aquitania, drawing Belgic and Celtic peoples with them. Afterwards turning eastwardly they invaded the Roman Provincia in southern Gaul, and through their victories threatened the great Republic. This was the peril of the Cimbri and Teutones, which Marius quelled by the waters of the Durance and then among the hills of Piedmont. The invasion did not change the ethnology of Gaul, which, however, was not altogether Celtic in Caesar's time. The opening sentences of his _Commentaries_ indicate anything but racial unity. The Roman province was mainly Ligurian in blood. West of the province, between the Pyrenees and the Garonne, were the "Aquitani," chiefly of Iberian stock. The Celtae, whose western boundary was the ocean, reached from the Garonne as far north as the Seine, and eastwardly across the centre of Gaul to the head waters of the Rhine. North of them were the Belgae, extending from the Seine and the British Channel to the lower Rhine. These Belgae also apparently were Celts, and yet, as their lands touched those of the Germans on the Rhine, they naturally show Teutonic affinities, and some of their tribes contained strains of Teuton blood. But it is not blood alone that makes the race; and Gaul, with its dominant Celtic element, was making Gauls out of all these peoples. At all events a common likeness may be discerned in the picture of Gallic traits which Caesar gives.[146]