e lands of others.
These conditions involve war, which is an important form of the
historical movement, contributing to new social contacts and fusion of
racial stocks. Raids and piratical descents are often the preliminary
of great historical movements. They first expand the geographical
horizon, and end in permanent settlements, which involve finally
considerable transfers of population, summoned to strengthen the
position of the interloper. Such was the history of the Germanic
invasions of Britain, the Scandinavian settlements on the shores of
Iceland, Britain, and France, and the incursions of Saharan tribes into
the Sudanese states. Among pastoral nomads war is the rule; the tribe, a
mobilized nation, is always on a war footing with its neighbors. The
scant supply of wells and pasturage, inadequate in the dry season,
involves rivalry and conflict for their possession as agricultural lands
do not. Failure of water or grass is followed by the decline of the
herds, and then by marauding expeditions into the river valleys to
supply the temporary want of food. When population increases beyond the
limits of subsistence in the needy steppes, such raids become the rule
and end in the conquest of the more favored lands, with resulting
amalgamation of race and culture.[154]

[Sidenote: Primitive war.]

The wars of savage and pastoral peoples affect the whole tribe. All the
able-bodied men are combatants, and all the women and children
constitute the spoils of war in case of defeat. This fact is important,
since the purpose of primitive conflicts is to enslave and pillage,
rather than to acquire land. The result is that a whole district may be
laid waste, but when the devastators withdraw, it is gradually
repopulated by bordering tribes, who make new ethnic combinations. After
the destruction of the Eries by the Iroquois in 1655, Ohio was left
practically uninhabited for a hundred and fifty years. Then the
Iroquoian Wyandots extended their settlements into northwestern Ohio
from their base in southern Michigan, while the Miami Confederacy along
the southern shore of Lake Michigan pushed their borders into the
western part. The Muskingum Valley in the eastern portion was occupied
about 1750 by Delawares from eastern Pennsylvania, the Scioto by
Shawnees, and the northeast corner of the territory by detachments of
Iroquois, chiefly Senecas.[155] The long wars between the Algonquin
Indians of the north and the Appalachian tribe