To the careful student of history, there is a very great deal more to be considered than the mere political facts that stand as landmarks along the path of progress which the nations have traversed since the plains of Iran poured forth their hosts westward. These facts are the mere externals that adorn the pages of historic lore, and embellish the memories of the great men who have lived in and moved the world at various times in various nations, or which clothe the lives of tyrants and usurpers