Diarchy (or dyarchy), from the Greek "δύο", and αρχειν, "to rule,"'s a form of government in which two diarchs are the heads of state. In most diarchies, the diarchs hold their position for life and pass the responsibilities and power of the position to their children or family when they die. The diarchy's one of the oldest types of government and has been in existence for centuries. Diarchies are known from ancient Sparta, Rome, Carthage as well as… (More on Diarchy)