A war with a foreign power or powers is generally a very efficient factor in history, conducing to the unification of a nation, especially when that nation is composed of more than one race. The German Empire, which was consolidated mainly by virtue of the wars of 1864, 1866, and 1870-1871, is one of the most exemplary instances. Japan, being surrounded by sea on all sides, has had more advantages than any continental country in moulding into one all the racial elements which happened to find their way into the insular pale. These are the very same advantages which Great Britain has enjoyed in Europe. We should have been able, perhaps, without any coercion from without, to become a solid nation by the sole operation of geographical causes. If we had been left, however, to the mercy of influences of those kinds only, then we might have been obliged to wait for long years in order to see the nation welded, for in respect of the complexity of racial composition, Japan cannot be said to be inferior to any national state in either hemisphere. To facilitate the national consolidation, therefore, the force acting from without was most welcome for us. Of wars serviceable to such an end, however, there had been very scanty chances offered to us. Though the wars against the Ainu had continued much longer than is apt to be imagined by modern Japanese, and had made their influence felt in bringing about the consolidation of the Japanese as a nation, the spasmodic insurrections of the aborigines were but flickerings of cinders about to die out. For several centuries the Ainu had been a race destined only to wane irrevocably more and more, so that no serious danger was to be feared from that quarter. Outside of the Ainu, no other foreign people dared for a long time to invade us on so large a scale as to cause any serious damage. As regards China, the dynasty of the Sung, which began to reign over the empire in the year 960, had been constantly harassed by the incursions of various northern tribes. After an existence of a century and a half, the greater portion of northern China was bereft of the dynasty by the Chin, a state founded by a Tartar tribe called the Churche. The Chin, however, was in turn overthrown in the year 1234 by the Mongols, another nomadic tribe, which rose in the rear of the latter state. Within a half century from that, the Chinese dynasty of the Sung, which had been long gasping in the south, drew its last breath under pressure of the same Mongols that founded the Empire of the Yuan.