Even in the Pre-Industrial Age, Obvious differences existed between class hierarchy or ethnicities. When an Empire does not specifically identify with one or tw

Even in the Pre-Industrial Age, Obvious differences existed between class hierarchy or ethnicities. When an Empire does not specifically identify with one or two ethnicities, most societies have always been wary of foreigners by calling them "Barbarians". Chichimecas, Mongols, Non-Greeks, Non-Han Chinese, etc.