Some remains of the Bronze Age civilization in North India appear to depict the worship of snake-deities. One such has a deity in human form with a hooded cobra over it, flanked on both sides by worshippers. In the Puranas the Naag[1] was a semi-divine being with a human torso and the lower half in the snake's form. However the same Puranas describe a Naag kingdom in the upper Narmada valley of Central India——it is stated that a Naag princess named Narmada was married to Purukutsa, the ruler of Ayodhya, and the ancestor of Bhagwan Raam.
Whether the Naags were mythical semi-divine beings, or a primitive non-Vedic tribe, or Vedic worshippers of snake divinities, remains an open question. But the state founded by a so-called Naag dynasty in the 3rd century CE was completely Vedic in character and ruled by the same customs and traditions as other contemporary Indian states.
In this dynasty 'Naag' was never a clan-name but merely a cognomen within the first name. The Vakatak rulers of Central India have left behind an epigraphic record mentioning a Maharaja Bhavanaag (4th century CE) with whose family they had a matrimonial alliance. This Maharaja was described as belonging to the Bharasiva family——the name originating from their having carried the load (Bhaar) of a Shivalinga on their shoulders.
Coins of this Maharaja Bhavanaag have been found in Padmavati near modern Gwalior (Central India). The other coins of the Bharasiva dynasty are of Maharajas Bhimnaag, Skandnaag, Brihspatinaag, Devnaag, and Vibhunaag.
It is the Puranic texts that call this dynasty 'Naag' and assert that other Naag dynasties were also established at Kantipura, Vidisa, and Mathura. However the contemporary coins discovered at Mathura are of rulers without the name 'Naag'....instead they bear the cognomen 'Mitra' and 'Datta' within the first name. These may have been vassals of the Kushans who declared independence at some point.
At this time the Gupta Empire spreads it rule over India, extinguishing all states in its path. Gupta records mention two such defeated rulers Ganapatinaag and Naagsena, either or both of whom may have been from 'Naag' families. Chandra Gupta II married Kubernaag, probably a Naag princess. Skanda Gupta appointed one Sarvanaag as governor of the Antarvedi province.
The Bharasiva Kings were credited with great valor, 'which caused the pure waters of the Bhagirathi to be sprinkled on their foreheads' as an inscription states. This is translated to mean the expansion of Bharasiva power towards the Himalayan foothills, from where the River Bhagirathi (Ganga) emerges into the plain. The Bharasiva are also credited with performing ten Ashvamedha sacrifices. This kingdom was a monarchy, which was absorbed by the Gupta Empire.
It must be repeated that 'Naag' was never a clan. The ancient texts make no reference to Naag gana or even a Naag janapad (clan-state). The Bharasiva state emerges as a monarchy, suggesting that the rulers only claimed Naag descent or gave a special importance to Naag worship. Later dynasties like the Kadamba in South India or the Karkotaka in Kashmir also claimed Naag descent——neither dynasty had Naag either as a surname or even as cognomen within the first name.
The Chhindak rulers of the Bastar region (Chhatisgarh) claimed Naag descent, were of the Kashyap gotra, had a hooded-snake banner, and a tiger-with-cub crest. One of their titles was 'Lord of Bhogavati', which as per the Puranas was the mythical capital of snake-deities in the subterranean world (patala loka).
The Sinda of North Mysore had the same banner and crest as the Chhindaks and were probably related to them. In later periods they told a mythical story for the origin of their banner and crest, where their ancestor was the human son of a snake king brought up by a tiger.
[1] The common Sanskrit word for snake was sarp, which became saanp in modern Hindi. Naag in modern Hindi is used primarily for the King Cobra, and this may have been the case in the ancient times too. In this text the spelling 'Naag' is used to avoid confusion with the 'Naga' tribes of NE India.