An emperor could conquer land with an army, but he could not hold it by force alone. Harmony had to be built. The ways emperors did this were:
- Letting local kings rule their own areas. In return for tribute and loyalty, emperors generally allowed regional kings or chiefs to continue to govern. People kept their own rulers, language and customs — so they felt less "conquered".
- A fair administration. Officials managed territories, collected taxes and maintained law and order. Aśhoka even ordered that men should never be imprisoned or tortured without good reason, and sent inspecting officers every five years.
- Respecting all faiths and schools of thought. Aśhoka encouraged all sects to study and accept each other's best teachings, and appointed officers of Dhamma to look after Buddhists, brahmans, Ājīvikas and Jains alike.
- Common laws, coins, weights and measures — so a trader from the north and one from the south could do business without confusion.
- Roads, rest houses, wells and shade trees — connecting people and making travel safe, which mixed cultures peacefully.
- Caring for people's welfare — granaries against famine, medical care for people and animals. Kauṭilya's rule: "In the happiness of his subjects lies the king's happiness."
- Encouraging art, learning and religion — stūpas, pillars, universities and centres of learning gave people a shared pride.
In short
Harmony came from tolerance + good administration + prosperity, not from the sword alone. Force could win a battle; only welfare could win the people.