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An
Alaric, an Attila, or a Zingis Khan, and the chiefs around them, might
fight for glory, for the fame of extensive conquests, but the true
cause that set in motion the great tide of northern emigration, and
that           to propel it till it rolled at different periods against
China, Persia, Italy, and even Egypt, was a scarcity of food, a
population extended beyond the means of supporting it.