Property came to be owned not by groups of kinfolk but by individuals, who increasingly won the right to buy and sell it at will. Their rights to that property were enforced not by kin but by courts and legal systems that had the power to settle disputes and compensate wrongs. In time, moreover, social rules were formalized as written laws rather than customs or informal traditions. These formal rules were used to organize the way that power was distributed in the system, regardless of the individuals who exercised power at any given time. Institutions, in other words, replaced individual leaders. Those legal systems were eventually accorded supreme authority over society, an authority that was seen to be superior to that of rulers who temporarily happened to command the state's armed forces and bureaucracy. This came to be known as the rule of law.