[Sidenote:  Natural boundaries as bases of ethnic and political boundaries.]

Nevertheless, all natural features of the earth’s surface which serve to check, retard or weaken the expansion of peoples, and therefore hold them apart, tend to become racial or political boundaries; and all present a zone-like character.  The wide ice-field of the Scandinavian Alps was an unpeopled waste long before the political boundary was drawn along it.  “It has not in reality been a definite natural line that has divided Norway from her neighbour on the east; it has been a band of desert land, up to hundreds of miles in width.  So utterly desolate and apart from the area of continuous habitation has this been, that the greater part of it, the district north of Trondhjem, was looked upon even as recently as the last century as a common district.  Only nomadic Lapps wandered about in it, sometimes taxed by all three countries.  A parcelling out of this desert common district was not made toward Russia until 1826.  Toward Sweden it was made in 1751."[340] In former centuries the Bourtanger Moor west of the River Ems used to be a natural desert borderland separating East and West Friesland, despite the similarity of race, speech and country on either side of it.  It undoubtedly contributed to the division of Germany and the Netherlands along the present frontier line, which has been drawn the length of this moor for a hundred kilometers.[341]

[Sidenote:  Primitive waste boundaries.]

Any geographical feature which, like this, presents a practically uninhabitable area, forms a scientific boundary, not only because it holds apart the two neighboring peoples and thereby reduces the contact and friction which might be provocative of hostilities, but also because it lends protection against attack.  This motive, as also the zone character of all boundaries, comes out conspicuously in the artificial border wastes surrounding primitive tribes and states in the lower status of civilization.  The early German tribes depopulated their borders in a wide girdle, and in this wilderness permitted no neighbors to reside.  The width of this zone indicated the valor and glory of the state, but was also valued as a means of protection against unexpected attack.[342] Caesar learned that between the Suevi and Cherusci tribes dwelling near the Rhine “silvam esse ibi, infinita magnitudine quae appelletur Bacenis; hanc longe introrsus pertinere et pro nativo muro objectam Cheruscos ab Suevis Suevosque ab Cheruscis injuriis incursionibusque prohibere."[343] The same device appears among the Huns.  When Attila was pressing upon the frontier of the Eastern Empire in 448 A.D., his envoys sent to Constantinople demanded that the Romans should not cultivate a belt of territory, a hundred miles wide and three hundred miles long, south of the Danube, but maintain this as a March.[344] When King Alfonso I. (751-764 A.D.) of mountain Asturias began the reconquest of Spain