In general it is thought that ‘Asura’ means the ultimate enemy-community of the ancient Aryans, and probably they were the aboriginal inhabitants of Bhāratavarṣa, and the Sura(s) or gods, conquering them, established their political and cultural dominance over the land. However, several Purāna-scholars have said that initially the Asura(s) were relatives and friends of gods–
asurā ye tadā teṣāṃ āsan dāyāda vāndhavāḥ.

In fact, from the ancient Brāhmaṇa-texts, this becomes clear that the Vedic men introduced themselves as devatā, and referred to others belonging to some other, similar community , as Asura(s). Possibly the performance of yajña was the reason of difference between the two communities. Perhaps the ‘gods’ were ‘gods’ because they used to perform yajña(s)–
yajñena vai devāḥ.
From the evidences in Vedic literature, it can be found that in early Vedic period , the term Asura was quite respectable, and all aristocratic gods– Marut, Dyau, Indra, Varuṇa, Tvaṣṭā, Agni, Vāyu, Pūṣā, Savitā or Parjanya– have been referred to as Asura.

In Veda, there are at least 105 mentions of Asura, and most of the memtions are in a respectable sense, only 15 times the term has been used in a negative term. The scholars are of the opinion that, as long as the gods and Asura(s) had been in friendly terms, the meaning of the term Asura was also positive. But gradually the similarity declined, and their antagonism increased, and the meaning of the term ‘Asura’ came to be used in a negative sense. So Asura became antagonistic to ‘Sure’, and thus came the proverbial status of the deva-asura antagonism. In Ṛgveda, from Vṛtra to Śamvarāsura , Pipru or Varcī– none of them lacked power. Śamvarāsura had possession over 90-99 fortresses. There were more than a milion follower-warriors under Varcī. In Purāṇa, Indra came to be known as Purandara, by destroying their pura(s)(cities) and army.

In Ṛgveda, Rudra is called ‘devatā-asura’. In Mahābhārata and Purāṇa, the Asura and demons are mostly found to be worshippers of Rudra-Śiva, and in general Rudra-Śiva is their protector.

In the tenth cycle of Ṛgveda it is found that the gods were able to conquer the Asura(s) completely, and hence their establishment as ‘gods’.

In terms of the usage of terms, the clash between gods and demons has given rise to a new term, that is, bhrātṛvya. In general bhrātṛvya means ‘the son of a brother’. But in societal terms of right to land-property, the brother’s sons are rival in heirship, so the term has come to mean ‘a natural enemy’. In Atharvaveda, there is evidence that this meaning of the term bhrātṛvya was alrady established in Vedic times. There is such a prayer to Agni– “O Agni, give us the strength to destroy bhrātṛvya(s)–
bhrātṛvya-kṣayanamasi/bhrātṛvyacātanaṃ se dāḥ svāhā.

It is from the concern over the right to the heavenly kingdom and heirship of property, the stepbrothers became bhrātṛvya or ‘enemy’. The evidence can be found in Tāṇḍya Mahābrāhmaṇa. In this Brāhmaṇa-text, the term bhrātṛvya has been several times applied to the Asura(s), in the sense of enemy–
parāsurā abhavannātmanā parāsya
bhrātṛvyobhavati ya evaṃ veda.
tāsu devāsurā aspardhanta te devā asurān
kāmadughābhya ākṣāreṇā’nudanta nudate
bhrātṛvyaṃ kāmadughābhya ākṣareṇa tuṣṭuvānaḥ.

In Vedic times, the antagonism between the Gods and Asura(s) was so prominently gounded in the mind of people that in Rāmāyaṇa- Mahābhārata and Purāṇa of later times, the Asura-community is mostly known for their hostility to gods, and this antagonism is something perennial. But in the 1st century AD, in Aṣṭādhyāyī Vyākaraṇa by Pāṇini, to illustrate the samāsa-formula, “yayāña virodhaḥ śāśvatikaḥ” (those who are bound to a perennial antagonism) the example is given ‘ahinakulam’, that is ‘snake and mole’. This compound-term is in Klīvaliṅga (klivalinga; neuter gender). Now, if the clash between the gods and demons was like that, there could be a term ending with neuter gender, but this did not happen. So it becomes evident that the antagonism between the gods and demons is not perennial, but merely naimittika, that is, based on some cause. They are not enemies by birth or race.

Many are of the conception that the Asura(s) had been the ancient non-Aryan people, and aboriginal inhabitants of Induia. The Vedic Vṛtrāsura or the Mahiṣāsura or Purāṇa were all kings of some non-Aryan tribes. But this conception is wrong and without any ground. In Mahābhārata and Purāṇa, it is a fact proved that the Asuras-demons were actually step-brothers of the gods.

Aditi was one wife of Prajāpati Kaśyapa, son of Brahmā, and the sons born of her womb, are called devatā, and the sons of his other wife Diti were Daitya, and the sons of Danu, his third wife, were Dānava(s). In fact, the term Asura, or even ‘Rākṣasa’ has been used as an epithet for Daitya-Dānava(s), and finally, it has come to be applied to those people who are antagonistic to gods.

Not only in Mahābhārata, in Tāṇḍya Mahābrāhmaṇa, written much earlier than Mahābhārata, it is said that– Prajāpati Brahmā had two kinds of sons– Devatā and Asura. Asura(s) were strong and the gods were weak. To oversome their weakness, the gods went to Prajāpati. Echoing Tāṇḍya Mahābrāhmaṇa, the 5th-6th century Vedic lixical scholar Yāska has given a suitable śavda-nirukti, saying that– Prajāpati created the Asura(s) from ‘su’ or good things, and he created the Asura(s) from a-su elements, that is, no good’, so they became ‘Asura'(s) to
sordevān asṛjata tat surānāṃ suratvamasora
-surān asṛjata tadasurāṇāmasuratvam.

In the commentary of the previously mentioned Nirukta-verse, the term ‘su’ means the following–
The “Sura’ or gods were born of the wide space of the Prajāpati’s body, and the Asura(s) were born out of a narrow space. In Vāyupurāṇa, this claim is also supported. There it is said that, when Prajāpati sat for tapasyā before creation, the Asura(s) came out of the ‘jaghanadeśa’ of his body, and that was before the creation of the gods. This statement is more in line with the Vedic theories, and moreover, it is also in conformation with the understanding of modern humanity. The scholars would say– ‘asu’ means ‘prāṇa-śakti or vital energy. Those who possess this vital energy, are Asura(s), they were born out of Brahmā’s vital energy–
tato’sya jaghanāt pūrvamasurā jajñire sutāḥ.
asuḥ prāṇaḥ smṛto vipraistajjanmānastato’surāḥ.

If the ‘ran’ pratyaya is added to ‘asu’, in the sense of ‘being’ (it has this), the meaning become as follows– those who have asu (vital energy) are Asura(s). This use of ‘ra’ pratyaya in the sense of ‘being’ is not many in Sanskrit, but there are some example which often go unnoticed — such as– Madhura, Śrīra(Śrīla), Vahura(Vahula), Adhara.

However, Vāyupurāṇa has got this meaning from the Vedic tradition, and it is already said that the gods have also been referred to as ‘Asura’ because of this sense of ‘possessing vital energy’. In one Ṛkmantra, explaining the meaning of ‘Asura’ applied in the sense of God, Sāyancrya has written, ‘as’ dhātu means ‘to throw away’, as if , it throws the enemies away– in this sense, the pratyaya ‘uran’ is added to ‘as’ dhātu, and the word Asura comes into use. Again, Asu means prāṇa. Asura can also mean ‘one who gives prāṇa or vital energy–
asura asukṣpaṇe asyati śtrun tyasuraḥ
āsaruran. asūna prāṇān rāti dadāti ityasuraḥ.

Asura means ‘having vital energy’–
sarvaṃ prāṇ ejati niḥsṛtam.

So, ‘Asura’ can as well indicate the Gods, and this is proved all the more by the epithet used to describe the Irānic god Varuṇa. In archaic Irānic, Varuṇa is ‘Asuro Mahat’- Ahura Mazda. Later, this respectable defining term for the Asura(s) has followed the process of ‘viṣamaccheda’ , as per lingustic terms. In fact, in Ṛgveda, the term ‘Asura’ is there, but the term ‘Sura’ is not in use. So, substracting ‘a’ from the fundamental term ‘Asura’ which existed in early Vedic age, the bnew term ‘Sura’ came to use, exclusively for the gods. And with the establishment of the term ‘Sura’ as denotative of gods, ‘Asura’ became the negative term, to be used for those who are antagonistic to gods.

However the Asura(s) might have been hostile to the gods, their close relation to gods is nowhere denied in Veda-Brāhmaṇa or Purāṇa-texts. From the term ‘Pūrvadeva’ as a synnonym for ‘Asura’ used in Amarakoṣa, it is also proved that the Asura(s) were also considered as Gods, later they came to be known as ‘Asura'(s). In Rāmāyaṇa, it is said in the context of Kaśyapa Prajāpati and Diti– the sons of Diti are Daitya(s). Earlier, the entire world was under the Daitya(s)–
teṣāmiyaṃ vasumatī purāsīt savanārṇavā.

So it is understood that the Gods drove the Daitya(s) away from their kingdom. And it is further reinforced that the Asura(s) are neither any non-Aryan ribe, nor the aboriginal inhabitants of India. They are step-brothers born of separate mothers but from the same father.

In Rāmāyaṇa-Mahābhārata-Purāṇa the clash between gods and demons is a common thing. Since the Brāhmaṇ texts, such examples can be found many times that the demons are fighting against the gods. In later times, only in Matsya-purāṇa, we find a chronological order of the battles between the gods and demons. Otherwise, there are occasional mention of some special war-incident. For instance, in Mārkaṇḍeyapurāṇa, it is said that, a hundred year’s battle continued between Indra and Mahiṣāsura–
devāsuramabhūd yuddhaṃ pūrṇamavdaśataṃ purā
mahiṣsurāṇāmadhipe devānāñca purandare.

Instead of citing hundreds of battles from Rāmāyaṇa and Mahābhārta, from Matsyapurāṇa it can be said that there were twelve major battles between the gods and demons. During the reign of demon-king Hiraṇyakaśipu, the battle between gods and demons took a terrible form, God Śrī Hari had to assume the Nṛsiṃhā-avatāra. Matsya Purāṇa says– The first battle took place at the time of the Nṛsiṃha-avatāra. The demon-king Hiraṇyakaśipu took the heavenly kingdom away from gods. Then, after the Nṛsiṃha-incarnation, the Gods defeated the Asura(s) and reoccupied their kingdom. The next battle took place during the reign of Vali. Finally the Vāmana-avatāra incarnated to captivate Vali. Hiraṇyākṣa, brother of Hiraṇyakaśipu, was slain at the time of the third battle.

The fourth battle took place at the time of Amṛtamanthana, and the demon-king Prahlāda got defeated by the gods. The fifth battle took place at the time of Prahlāda’s son Viriocana, in that starry war, Virocana got killed. The demon-king Vali was the son of Virocana, and grandson of Prahlāda. But his name comes earlier, because of the grace of Vāmanadeva-incarnation. In the sixth battle, Āḍī-vaka was killed, the seventh battle was against Tripurāsura, in this battle the ultimte deermininig role was that of Mahādeva. In the ninth battle between gods and demons, Vṛtrāsura was slain. Ghorāsura was killed in the tenth battle called Halāhala. Vipracitti was killed by Indra in the eleventh battle, and the twelfth battle is called Kolāhala. Along with the documentation of these twelve battles, Matsyapurāṇa also gives a major information– only during the time of Vali, the gods had a more or less friendly connection with the Asura(s).

Another important information about the Asura(s) is that, though they are antagonistic to gods, they also perform asceticism etc. as per the Aryan system. Asura(s), Dānava(s) and Rākṣasa(s) have performed tapasyā so many times in order to get worldly wealth, to rule over the gods, or to get the ownership of all the three worlds, to achieve immortality, or even, to surpass the boon-giving Supreme God. They used to perform tapasyā in order to please anyone among Brahmā, Viṣṇu and Maheśvara. Viṣṇu was not so much of a boon-giver to the demons, but Brahmā assumed the chief role in granting boons to the demons. Another favourite Deity of the demons, regardins this boon-giving, was Rudra-Śiva.

But above everything, this should be made clear that Asura is a generic name. Daitya, Dānava, Rākṣasa, Kavandha, Piśāca are also known as the Asura(s), and in a text as ancient as Śatapatha Brāhmaṇa, the term Rākṣasa has been pronounced with ‘Asura’ several times, but in the context of putting up a battle-challenge against the Gods, Rākṣasa(s) do not fogure so much as the Asura(s0. But in the context of yajña(s), it is said that the Gods are worried about the Asura(s) and Rākṣasa(s)–
te asura-rākṣsebhya āsaṅgād vibhayāñcakruḥ.
Here, though this dvandvasamāsa is used in plural terms, in Śatapatha Brāhmaṇa itself, the dual nature of the dvandvasamāsa gets dissolved, and ‘Asura’ and ‘Rākṣasa’ became one in meaning.