The ancient Indian government evolved over time from simple tribal structures to more complex empires. Early societies were led by tribe chiefs who appointed helpers to oversee society. As kingdoms grew, a king or maharaja became the head of state and administration, ruling with the help of a council of ministers. By the 6th century BC, 16 great kingdoms had been established across India. The government had elements of modern systems, with legislative, executive, and judicial branches headed by the king. Officials tracked public opinion and population changes, and the military was well-trained, helping the large empires maintain effective control and administration.