The period of Mauryas is also known for the birth of Jainism and Budhism as well as for the 'Arthasastra'. The word Arthasastra means the science of acquiring wealth and protection of the earth. 'Artha' also stood for material well being such as wealth, on which the prosperity of humans depended. Kautilya, also known by the name Chanakya, is said to have written the treatise on Arthasastra during the reign of Chandragupta Maurya.

The treatise covers all subjects required by the King to rule over his Kingdom. It starts with how a King should conduct himself, subjects he should learn and the daily routine he has to follow to be a good ruler. The book covers the subjects of law, commerce, budget and accounts, foreign affairs and defence. For an efficient government and implementation of policies, Chanakya also mentions in detail, the administrative organization required.

Of specific interest to the study of military history is the section on Defence and War. As per Kautilya, the King had three responsibilities which were:

  • Protection of the people from external aggression.
  • Enlargement of territory by conquest.
  • Welfare of the people - Wars according to him were of four kinds: Mantrayuddha or war by counsel or diplomatic war. `Prakasayuddha' or open warfare i.e, a set piece battle.
  • Kutayuddha is concealed war or secret war/psychological war.
  • Gudayuddha or Clandestine war. Clandestine war meant war by covert operations using agents, double agents, etc.

Kautilya given the final authority to the king in all matters of administration. Among the seven components of the state the king is given the primary position. The Saptangas (seven limbs) of the state are: King (Swami), Danda (Arny), Janapada (Territory), Amatya (minister), Mitra (Friend), Durga (Fort), Kosa (Treasure)

Shatru (Enemy) - The 8th element added by Arthasastra.

Kautilya mentions that the king must undergo military training.

Kautilya also refers to Chaturangbala (Cavalry, Infantry, Chariot and Elephants) as the main components of Army. Each one of them was placed under a commander. He also mentions about medical service to the Army, the recruitment policy, war plans, fortification, etc.