Almost all the great emigrations of nations have been and continue to be from the cold and barren region of Scythia, because from the population there being excessive, and the soil ill able to support them, they are forced to quit their home, many causes operating to drive them forth and none to keep them back. And if, for the last five hundred years, it has not happened that any of these nations has actually overrun another country, there are various reasons to account for it. First, the great clearance which that region made of its inhabitants during the decline of the Roman Empire, when more than thirty nations issued from it in succession; and next, the circumstance that the countries of Germany and Hungary, whence also these nations came, are now so much improved that men can live there in comfort, and consequently are not constrained to shift their habitations. Besides which, since these countries are occupied by a very warlike race, they serve as a sort of bulwark to keep back the neighbouring Scythians, who for this reason do not venture to attack them, nor attempt to force a passage. Nevertheless, movements on a great scale have oftentimes been begun by the Tartars, and been at once withstood by the Hungarians and Poles, whose frequent boast it is, that but for them, Italy and the Church would more than once have felt the weight of the Tartar arms. Of the nations of whom I have been speaking, I shall now say no more. CHAPTER IX.—_Of the Causes which commonly give rise to Wars between States_. The occasion which led to war between the Romans and Samnites, who for long had been in league with one another, is of common occurrence in all powerful States, being either brought about by accident, or else purposely contrived by some one who would set war a-foot. As between the Romans and the Samnites, the occasion of war was accidental. For in making war upon the Sidicinians and afterwards on the Campanians, the Samnites had no thought of involving themselves with the Romans. But the Campanians being overpowered, and, contrary to the expectation of Romans and Samnites alike, resorting to Rome for aid, the Romans, on whose protection they threw themselves, were forced to succour them as dependants, and to accept a war which, it seemed to them, they could not with honour decline. For though they might have thought it unreasonable to be called on to defend the Campanians as friends against their own friends the Samnites, it seemed to them shameful not to defend them as subjects, or as a people who had placed themselves under their protection. For they reasoned that to decline their defence would close the gate against all others who at any future time might desire to submit themselves to their power. And, accordingly, since glory and empire, and not peace, were the ends which they always had in view, it became impossible for them to refuse this protectorship.