c. The à priori likelihood or unlikelihood of a Kelt-iberic mixture.

The last is considerable.

The evidence that gives us Kelts at all in the Peninsula gives us them for three-fourths of its area; indeed, Andalusia is the only part wherein reasons of some sort or other for their presence, cannot be discovered. We find traces of them in the valleys of the Ebro, the Guadiana, the Tagus, and the Douro, and we find them also on the high central table-lands that form the water-shed. Such being the case, what must be our view of their chronological relations to the Iberi? Are they the older occupants of Spain and Portugal, or the newer? If the newer, the displacement must have been enormous. If the older, whence are we to bring the Iberians? So great are the difficulties of this alternative, that the fact itself requires extraordinary caution before we admit it at all. Let us deal with the evidence in this cautious spirit.

The external evidence is clear and decisive. To go no further than Strabo, we have Kelts in the north, Kelts between the Guadiana and the Douro, and Kelts in the interior.

At the head-waters of the Guadiana, Posidonius places the Keltiberians, in which parts they “increased in numbers, and made the whole of the neighbouring country Keltiberic.” This is the country on each side of the Sierra de Toledo, or New Castile, the very centre of Spain, and, as such, an unlikely place for an immigrant population, whether we look to its distance from the frontier, or to its mountainous aspect. They are carried, at least, as far north as the mountains of Burgos, and to the upper waters of the Douro on one side, and the Ebro on the other. So that Old Castile, with parts of Leon and Aragon, may be considered as Keltiberic. This is the first division.

In the south of Portugal comes the second, i.e., in Alemtejo, or the parts between the Tagus and the Guadiana. Here are the Celtici of the classical writers.

The third section is found in the north of Portugal, and in the neighbourhood of Cape Finisterre. Here Strabo places the Artabri, and close to them Celtici and Turduli of the same nation with those of the south, i.e., those of Alemtejo. His language evidently suggests the idea of a migration. Such is the Keltic area as determined by external evidence, and it cannot be denied that it is very remarkable. It is of considerable magnitude, but very discontinuous and unconnected.

The internal evidence is wholly of one sort, viz., that which we collect from the names of geographical localities. One of the common terminations in the map of ancient Gaul is the word -briga (as in Eburo-briga), which takes the slightly different forms of -briva, and -brica—Baudo-brica, Samaro-briva. Now compounds of -briga are exceedingly common in Spain. They occur in all the parts to which Celtici or Celtiberi are referred, and in a great many more besides. Hence the internal evidence—as far, at least, as the compounds in -briga are concerned—gives us a larger Keltic area (or more Keltiberians) than the testimony of authors; indeed it gives us the whole of the peninsula except Andalusia, a fact which explains the import of a previous remark as to absence of compounds ending in -briga south of the Sierra Morena. It is rare, too, in Catalonia—perhaps non-existent.

Tested, however, by the presence of the form in question, Valentia on the west, and all Portugal (the ancient Lusitania) on the east, were Keltiberic—as may be seen by reference to any map of ancient Spain.

But there are serious objections to the usual inference from this compound. It is nearly the only geographical term of which the form is Keltic. And this is a remarkable instance of isolation. The terminations -durum, -magus, and -dunum, all of which are far commoner in Gaul than even -briga itself, are nowhere to be found. Neither are the Gallic prefixes, such as tre-, nant-, ver-, &c. Hence, it is strange that, if Spain were Keltic, only one Keltic form should have come down to us. Where are the rest? I am inclined to believe that the inference as to such a Spanish name as, e.g., Talo-briga, being Keltic, on the strength of such undoubted Gallic words as Eboro-briga, is no better than the assertion that the Jewish name Samp-son was in the same category with the English names John-son and Thomp-son would be. Such accidental resemblances are by no means uncommon. The termination -dun is as common in Keltic, as the termination -tun is in German. Yet they are wholly independent formations. At the same time I cannot deny that the internal and external evidence partially support each other.