Disclaimer: Some facts and figures might have been exaggerated, others downplayed and few might have been mythologized. Please keep in mind the poet's bias while reading the following verses from Rig Veda.
Shambara was one of the mighty kings of the black skinned people who lived in India before the arrival of Indo-Aryans. He's said to have lived in the mountains, and it's claimed by Rig Veda that it took 40 years for the Indo-Aryans to conquer his territory.
According to a paper, Shambara was a Munda / proto-Munda king and the mountain has been identified as Marang Buru (Parasnath) Mountain
in present day Giridih district, Jharkhand, India.
Let's go ahead and enjoy the verses!
Rig Veda 6.31.4
You have destroyed the 100 impregnable cities of the Dasyu, Shambara, when sagacious Indra, you, who are brought by the libation, have bestowed in your liberality riches upon Divodasa presenting to you libations, and upon Bharadvaja hymning your praise.
Commentary by Sayanacharya: Dasyu, Shambara: Shambara is an Asura. Dasyu and Asura appear to be synonymous.
Rig Veda 4.16.13
You have subjugated Pipru and the mighty Mrigaya for the sake of Rijishvan, the son of Vidathin, you have slain the fifty thousand Krishnas (black people); and, as old age (destroys) life, you have demolished the cities (of Shambara).
Commentary by Sayanacharya: Mrigaya = name of an asura; Vidathin = a raja; fifty thousand Krishnas = Rakshasas of a black colour, Krishna Varnani Rakshasamsi.
Rig Veda 6.47.2
The savoury Soma, drunk on this occasion, has been most exhilarating; by drinking of it Indra has been elevated to the slaying of Vritra, and he had destroyed the numerous hosts of Shambara and the 99 cities.
Rig Veda 2.12.11
He, who discovered Shambara dwelling in the mountains for 40 years; who slew Ahi, growing in strength, and the sleeping son of Danu; he, men, is Indra.
Rig Veda 8.96.16
As soon as you were born, Indra, you were an enemy to those seven who had no enemy; you recovered the heavens and earth when concealed (in darkness); you cause joy to the mighty worlds.
Commentary by Sayanacharya: Thoses even who had no enemy: Krishna, Vritra, Namuchi, Shambara etc.; or, you were an enemy to those who had no enemy, on behalf of the seven sages (the Angirasas). i.e., inorder to recover their cows.
Rig Veda 6.18.13
That exploit is celebrated in the present day (which you have) achieved for Kutsa, for Ayu, for Atithigvave; to him you have given many thousands (of riches), and you have quickly elevated Turvayana over the earth by your power.
Commentary by Sayanacharya: Turvayana: same as Divodasa, to whom Indra gave the spoils of Shambara.
Rig Veda 3.47.4
They who encouraged you, Maghavan, to slay Ahi, who (aided you) in the conflict with Shambara, and in the recovery of the cattle, and who, possessed of wisdom, contribute verily to your exhilaration, with them, the troop of the Maruts, do you Indra, drink the Soma.
Rig Veda 5.29.6
Whereupon Maghavan has destroyed with his thunderbolt at once his (Shambara's) ninety and nine cities; the Maruts glorifying Indra in a common dwelling with the Triṣṭubh hymn, he destroyed the bright (city of the asura).
Rig Veda 6.26.3
You have animated the sage with (the hope of) obtaining food; you have cut to pieces Shushna for Kutsa, the donor of the oblation; you have struck off the head (of Shambara), imagining himself invulnerable, intending to give plural asure to Atithigvan.
Rig Veda 2.19.6
The radiant Indra subjected to Kutsa, his charioteer, (the asuras), Shushna, Ashusha, and Kuyava; and, for the sake of Divodasa, demolished the 99 cities of Shambara.
Commentary by Sayanacharya: Ashusha, he who is not to be dried up; perhaps, an epithet of Shushna, an Asura.
Rig Veda 8.97.14
Indra, mightiest Shakra, you know how to destroy those cities (of Shambara) by your strength at you allworlds tremble, thunderer - heaven and earth (tremble) with fear.
Rig Veda 1.103.8
Inasmuch, Indra, as you have slain Shushna, Pipru, Kuyava and Vritra, and destroyed the cities of Shambara, therefore may Mitra, Varuṇa, Aditi - ocean, earth, and heaven, grant us that (which we desire).
Rig Veda 7.99.5
Indra and Vishnu, you have demolished the 99 strong cities of Shambara; you have slain atonce, without resistance, the 100 thousand heroes of the Asura Varcin.
Rig Veda 1.112.14
With those aids by which you defended the mighty and hospitable Divodasa, (when, having undertaken) the death of Shambara, he hid himself in the water (through fear of the asuras); by which you protected Trasadasyu in war; with them, Ashvins, come willingly hither.
Commentary by Sayanacharya: Divodasa was a king; he is called atithigva, the cherisher of guests (atithi); Trasadasyu was the son of Purukutsa.
Rig Veda 2.14.6
Priests, present the Soma to him who, with the adamantine (thuderbolt), demolished the 100 ancient cities of Shambara, and cast down the hundred thousand (descendants) of Varcin.
Commentary by Sayanacharya: Varcin, an asura who reviled Indra and was consequently destroyed, with all his children and dependants.
Rig Veda 4.26.3
Exhilarated (by the Soma beverage) I have destroyed the 99 cities of Shambara, the hundredth I gave to be occupied by Divodasa when I protected him, Atithigva, at his sacrifice.
Rig Veda 1.54.6
You have protected Narya, Turvasha, Yadu and Turviti, of the face of Vayya; you have protected their chariots and horses in the unavoidable engagement; you have demolished ninety-nine cities (of Shambara).
Commentary by Sayanacharya: Turvasha may be Turvasu, son of Yayati, since another son of Yayati, Yadu is also named. Turviti is a Rishi.
Rig Veda 1.59.6
I extol the greatness of that showerer of rain whom men celebrate as the slayer of Vritra; the Agni, Vaishvanara, slew the stealer (of the waters) and sent them down (upon earth), and clove the (obstructing) cloud.
Rig Veda 6.47.22
Prastoka has given to your worshipper, Indra, ten purses of gold, and ten horses, and we have accepted this treasure from Divodasa, the spoil won by Atithigva from Shambara.
Rig Veda 6.26.5
Indra, who are the subduer (of foes), you have achieved a glorious (deed), inasmuch as you have scatered, hero, the hundreds and thousands (of the host of Shambara), have slain the Dasyu Shambara (when issuing) from the mountain, and have protected Divodasa with marvellous protections.
Rig Veda 1.101.2
We invoke to be our friend, Indra, who is attended by the Maruts; he who, with increasing wrath, slew the mutilated Vritra and Shambara, and the unrighteous Pipru, and who extirpated the unabsorbable Shushna.
Commentary by Sayanacharya: Shambara and Pipru are Asuras; Pipru = avratam, not performing or opposing vratas, religious rites; ashusham shushnam = the dryer up, i.e. who cannot be absorbed.
Rig Veda 6.47.21
Indra, becoming manifest from his abode (in the firmament), dissipates, day by day, the resembling glooms, (so that he may distinguish) the other portion, (or the day); and the showerer has slain the two wealth-seeking Dasas, Varcin and Shambara, in (the country of) Udavraja.
Rig Veda 1.130.7
For Pur, the giver of offerings, for the mighty Divodasa, you, Indra, the dancer (with delight in battle), have destroyed 90 cities; dancer (in battle), you have destroyed them with (your thunderbolt), for (the sake of) the giver of offerings. For (the sake of) Atithigva, the fierce (indra) hurled Shambara from off the mountain bestowing (uon the prince) immense treasure, (acquired) by (his) prowess; all kinds of wealth (acquired) by (his) prowess.
Rig Veda 6.18.8
He who is never perplexed, who is no engenderer of that which is in vain, whose name is renowned, who promptly (exerts himself) for the overturning of the cities (of the asuras), and for the destruction (of his foes); you, (Indra), have indeed slain Cumuri, Dhuni, Pipru, Shambara, and Shushna.
Rig Veda 1.51.6
You have defended Kutsa in fatal fights with Shushna; you have destroyed Shambara in defence of Atithigva; you have trodden with your foot upon the great Arbuda; from remote times were you born for the destruction of oppressors.
Commentary by Sayanacharya: Shushna, Shambara and Arbuda are asuras. Kutsa is a Rishi; Atithigva = hospitable, Divodasa.
Rig Veda 9.61.2
(Which overturned) the cities in a moment, and for the sake of the devout Divodasa (subdued) Shambara, and then that Turvasha and Yadu.
Rig Veda 4.30.14
You have slain the Dasa Shambara, the son Kulitara hurling him off the huge mountain.
Rig Veda 1.54.4
You have shaken the summit of the spacious heaven; you have slain Shambara by your resolute self; you have hurled with exulting and determined mind the sharp and bright-rayed thunderbolt against assembled Asuras.
Rig Veda 7.18.20
Your favours, Indra, and your bounties, whether old or new, cannot be counted like the (recurring) dawn; you have slain Devaka, the son of Manyamana, and of thine own will, has cast down Shambara from thevast (mountain).
Rig Veda 6.43.1
This Soma, in the exhilaration of which it is known that you had subdued Shambara for (the sake of) Divodasa, is poured out, Indra, for you; drink.
Casteism and racism in India is much deeper than we think it is
Now it makes sense why Brahmins and their braindead parrots deny Aryan migration, despite overwhelming amount of evidence confirming it