Kings Depended Upon Their Queens
The [ancient Egyptian] kings had to take their army out every year to punish those who had rebelled and to intimidate those who had not. They trained their heirs to shoot the bow and work the chariot, to become the foremost warrior of Egypt, to command the army, and the professional officer corps. During campaigning season the kings were absent from Egypt and they depended upon their queens (who had the authority to rule but who could not supplant the king) to supervise the vizier and break him if he appeared to be a threat to the king. This system worked as long as the king was strong enough to check the power of vizier, queen, and priest.