of Spain from the Saracens, he adopted the same
method of holding the foe at arm's length. He seized Old Castile as far
as the River Duoro, but the rest of the province south of that stream he
converted into a waste boundary by transporting the Christians thence to
the north side, and driving the Mohammedans yet farther southward.[345]
Similarly Xenophon found that the Armenian side of the River Kentrites,
which formed the boundary between the Armenian plains and the highlands
of Karduchia, was unpeopled and destitute of villages for a breadth of
fifteen miles, from fear of the marauding Kurds.[346] In the eastern
Sudan, especially in that wide territory along the Nile-Congo watershed
occupied by the Zandeh, Junker found the frontier wilderness a regular
institution owing to the exposure of the border districts in the
perennial intertribal feuds.[347] The same testimony comes from
Barth,[348] Boyd Alexander,[349] Speke,[350] and other explorers in the
Sudan and the neighboring parts of equatorial Africa.

[Sidenote: Border wastes of Indian lands.]

The vast and fertile region defined by the Ohio and Tennessee rivers,
lay as a debatable border between the Algonquin Indians of the north
and the Appalachians of the south. Both claimed it, both used it for
hunting, but neither dared dwell therein.[351] Similarly the Cherokees
had no definite understanding with their savage neighbors as to the
limits of their respective territories The effectiveness of their claim
to any particular tract of country usually diminished with every
increase of its distance from their villages. The consequence was that a
considerable strip of territory between the settlements of two tribes,
Cherokees and Creeks for instance, though claimed by both, was
practically considered neutral ground and the common hunting ground of
both.[352] The Creeks, whose most western villages from 1771 to 1798 were
located along the Coosa and upper Alabama rivers,[353] were separated by
300 miles of wilderness from the Chickasaws to the northwest, and by a
150-mile zone from the Choctaws. The most northern Choctaw towns, in
turn, lay 160 miles to the south of the Chickasaw nation, whose compact
settlements were located on the watershed between the western sources of
the Tombigby and the head stream of the Yazoo.[354] The wide intervening
zone of forest and canebrake was hunted upon by both nations.[355]

Sometimes the border is preserved as a wilderness by formal a