The slave armies were an attempt to use a minority elite, that was individually powerless and collectively powerful. Such a formula was inherently unstable. Political eunuchism, or the use of eunuchs in government, was a more explicit attempt at reining in the dynastic excesses of tribalism. A eunuch might hold power, but he could not pass that power on to his son. His loyalty had to be personal, as it could not be dynastic. Both slave armies and eunuchs depended on tearing men out of the tribal system, through slavery or castration, to compensate for the essential instability of any system of governance in the region.