The state is defined as a political organism, which unites and co-ordinates social forces according to precise rules. There were two types of states prevailing in ancient India.

Kingdom or monarchies enjoyed immense popularity and were the most prevalent form of government in ancient India. They are defined as a state having a form of government in which the supreme power is vested in one individual, who is the head of the state, the king.
A republic on the other hand is referred to as state in which the supreme power rests in the people and their representatives or officers, as opposed to one governed by a king or similar ruler; a commonwealth. Although while classifying a system as republic, we must keep in mind that a republic need not always be democratic as was the case in ancient India where power vested not in the whole body of citizens but in a small aristocratic class. Thus Sparta, Athence, Rome, Medieval Venice have all been described as republics though none of them possessed that full democratic character which is now considered the distinguishing feature of a republic.
Speculation regarding the origin of kingship occurs in the Vedic literature. Aitareya Brahmana refers to war between the devas(gods) and danavas(demons) in which gods were repeatedly defeated. The gods then realized the reason for their defeat was the absence of a leader to lead them while their counterparts had one, the king. They decided to try this experiment, elected a king in either Indra or Varuna, which the texts are unclear about and triumphed over the demons. This clearly indicates that the kingship arose out of a military necessity, and that a king must be a capable general whose leadership must be acknowledged by all.
Some writers have averred that monarchy was the only form of government known to ancient India, dismissing republics as nothing more than tribal