Indra (इन्द्रः)

Indra (Samskrit: इन्द्रः) is the adhipati (leader) of the Devas and rules Svargaloka, also called as Amaravati. He is the presiding deity of rain and thunderstorms. Indra is the most important deity worshiped in the Rig veda mantras, and innumerable, anecdotes, legends and events are connected with Him, through different yugas or ages in different puranas.

Indra is also described as a position, which may be achieved by one who performs one hundred aswamedha yagnas.

परिचय || Introduction

Indra, is the most celebrated deity and worshiped since ages in Sanatana Dharma. He is highly revered for his power as a slayer of rakshasas or demons and asuras and protector of rishis and dharma as seen in the Vedas.

In Mahabharata and Puranas, numerous anecdotes of Indra describe his rivalries, wars, vices, disguises, hasty actions and decisions, often seeking refuge in either Brahma, Vishnu, or Mahadeva for overpowering his adversaries. Apart from all these qualities he is revered for his power and protection of Dharma. Following are the different aspects associated with Indra across the various texts.

• यज्ञपालकः || Yagnapalaka : As the Protector of Yagnas, he plays a significant role. There are more than 250 Rk Suktas that glorify Indra by performance of yagnas and offering of Soma rasa for him, he is the chief receiver to be pleased at any yagna.
• सुरपतिः || Surapati : As a protector, Indra rules over the earth and heavens, suras or devatas including Maruthas and other beings such as Gandharvaas, Apsaraas, Asuraas and Rakshasas, He is the master of all these entities including nishadas.
• स्वर्गाधिपतिः || Svargaadhipati : He is engaged in a constant vigil to protect Svargaloka which is the home for all ratnas (gems or treasures) and nidhis (divine heavenly treasures) such as Kalpavriksha (wish-fulfilling tree studded with precious stones), Amrita (nectar), Kaamadhenu (divine wish-fulfilling cow), Airavata (divine elephant), Ucchaisravasa (divine horse), and Parijatavriksha (divine flowering tree with unfading flowers) among other things.
• मरुतवान् || Marutavaan : As the presiding devata for clouds and rain, He also controls thunder, lightning, and his discord is often seen as heavy downpour and thunderstorms. In Shrimad Bhagavatam, Bhagavan Srikrishna protects the residents of Vrindavan from the wrath of Indra who impounds them with incessant heavy rain for refusing to worship Him. Similarly, in Mahabharata, Khandavavana dahana, Indra protects his friend, Takshaka from Agni, who wants to burn the forest.
• गोरक्षकः || Gorakshaka : He plays a chief role in the retrieval of the cows hidden by Panis in the mountains. Angirasa rushi the "padajna" helps him locate the cows and then he fights Panis to bring them back.

व्युत्पत्तिः || Etymology

Amarakosha defines the following about Indra in स्वर्गवर्गः (Prathama kanda Slokas 41- 44)

"इन्द्रो मरुत्वान्मघवा बिडौजाः पाकशासनः । वृध्दश्रवाः सुनासीरः पुरुहूतः पुरंदरः ॥" (Amara 1. स्वर्ग. 41)

"जिष्णुर्लेखर्षभः शक्रः शतमन्युर्दिवस्पतिः। सुत्रामा गोत्रभिद्वज्री वासवो वृत्रहा वृषा॥" (Amara 1. स्वर्ग. 42)

"वास्तोष्पतिः सुरपतिर्बलारातिः शचीपतिः। जम्भभेदी हरिहयः स्वाराण्नमुचिसूदनः॥ " (Amara 1. स्वर्ग. 43)

संक्रन्दनो दुश्च्यवनस्तुराषाण्मेघवाहनः। आखण्डलः सहस्राक्ष ऋभुक्षाः ------- ॥ " (Amara 1. स्वर्ग. 44)

Like many other deities, Indra is also called by many names - मरुत्वान् ॥ Marutvaan, Maghavaan, Paakashasana, Vriddhasravaaha, Sunaaseera, Puroohuta, Purandara, शक्र Shakra, Shatamanyu, Sutrama, Vritraha, मेघवाहन Meghavaahana, Vajri, Gotrabhit, Namuchisudhana, Surapati, Sachipati and others.

Indra is derived from the dhatu (root) "इन्द" meaning "परमैश्वर्य्ये " parama aishwarya (wealthy).

Nirukti : Maharshi Yaska in his Nirukti (10.8) explains the meaning of Indra as follows

1. इरां दृणातीति वा ॥ irāṁ dr̥ṇātīti vā ॥

2. इरां ददातीति वा ॥ irāṁ dadātīti vā ॥

3. इरां दधातीति वा ॥ irāṁ dadhātīti vā ॥

4. इरां दारयतीति वा ॥ irāṁ dārayatīti vā ॥

5. इरां धारयतीति वा ॥ irāṁ dhārayatīti vā ॥

6. इन्दवे द्रवतीति वा ॥ indave dravatīti vā ॥

7. इन्दौ रमत इति वा ॥ indau ramata iti vā ॥

8. इन्धे भूतानीति वा ॥ indhe bhūtānīti vā ॥

9. तद्यदेनं प्राणैः समैन्धंस्तदिन्द्रस्येन्द्रत्वम् ॥ tadyadenaṁ prāṇaiḥ samaindhaṁstadindrasyendratvam ॥

10. इदं करणादित्याग्रयणः ॥ idaṁ karaṇādityāgrayaṇaḥ ॥

11. इदं दर्शनादित्यौपमन्यवः ॥ idaṁ darśanādityaupamanyavaḥ ॥

12. इन्दतेर्वौश्वर्यकर्मणः ॥ indatervauśvaryakarmaṇaḥ ॥

13. इन्दञ्छत्रूणां दारयिता वा द्रावयिता वा अादरयिता च यज्वनाम् ॥ indañchatrūṇāṁ dārayitā vā drāvayitā vā aādarayitā ca yajvanām ॥

According to Shabdakalpadhruma इरा has different meanings; two of the relevant ones here are Prithvi or Bhumi (earth) and Jalam (water).  

Meaning of Indra is thus, one who is दारयति (दारयति ज्ञातिबन्धूनिति as per Shabdakalpadhruma) closely related to water (Indra is related to clouds which give water), who bears water (rain bearing clouds), who ददाति gives water (clouds give rains), who holds (clouds hold water), one who pierces the clouds and supplies water for the growth of plants. In another sense one who makes prithvi (earth) pierce and make crops grow thus providing grains.  

Megha (clouds), Indu (Moon) and Maruts (winds) are all interrelated and are the fundamental cause for nourishment of all tree and plant species including medicinal plants. Thus Indra is the power which can cut through the clouds and provide rain for the sake of loka kalyana, for the loka sangraha. 

धा Dha root word means धारणे to bear and पुष्टौ to supply or nourish. Because Indra showers rain water, and धारयति nourishes the plants and thus he provides food or fuel for living beings (इन्धे भूतानीति वा).  Indra also one rejoices or shines in presence of Chandra (moon) as meant in इन्दौ रमत.  

For seeds to grow in the form of plants, the earth has to be very favorable, when bhudevi becomes coarse and hard, agriculture is not possible. A farmer tills the land with the plough piercing the land, Indra establishes the dharma “iram utpadayatum karshaka mukhe kena bhumi vidarayati iti indrayaha”  

Indra is also called सोमपा || Somapa (One who delights in drinking soma rasa).

Role of Indra

In the Vedas, Indra has a very significant position as a Protector of Yagnas and the chief recipient of havish or yagna offerings. He is also the most feared destroyer of Panis, Dasyus and Asuras like Vritra, who obstructed the performance of yagnas. He is also the chief deity in Somayaga, and is the chief beneficiary of Somarasa.

In the Puranas, the significance of Indra is limited as the protector of Devaloka, whose activities are restricted to safeguarding his position as Indra. In the continuous battle between devathas and asuras, Indra stands as the leader of devathas. Indra fights many asuras namely, Vritra, Namuchi, Sushnaha, Sambhara, Thuni, Chumuri, Varchi.

The following Rig Veda mantras (2.12.1 to 15) describe the greatness of Indra as the chief of devatas, the protector of earth and cows, as one who cut the wings of the mountains as the slayer of Vala and Vrtrasura.

यो जात एव प्रथमो मनस्वान् देवो देवान् क्रतुना पर्यभूषत् | यस्य शुष्माद् रोदसी अभ्यसेतां नृम्णस्य मह्ना स जनास इन्द्रः || (Rig. Veda. 2.12.1)

yō jāta ēva prathamō manasvān dēvō dēvān kratunā paryabhūṣat | yasya śuṣmād rōdasī abhyasētāṁ nr̥mṇasya mahnā sa janāsa indraḥ || (Rig. Veda. 2.12.1)

Summary : As soon as he was born, who was decorated as the Chief of Devas, know that he is Indra.

यः पर्थिवीं व्यथमानाम दृंहद् यः पर्वतान् प्रकुपिताँ अरम्णात् | यो अन्तरिक्षं विममे वरीयो यो दयामस्तभ्नात् स जनास इन्द्रः || (Rig. Veda. 2.12.2)

yaḥ parthivīṁ vyathamānāma dr̥ṁhad yaḥ parvatān prakupitām̐ aramṇāt | yō antarikṣaṁ vimamē varīyō yō dayāmastabhnāt sa janāsa indraḥ || (Rig. Veda. 2.12.2)

Summary : He who gave relief to the earth from distress, one who laid at rest the mountains (from flying), who supported the heavens, know that he is Indra.

यो हत्वाहिमरिणात सप्त सिन्धून् यो गा उदाजदपधा वलस्य | यो अश्मनोरन्तरग्निं जजान संवृक् समत्सु स जनास इन्द्रः || (Rig. Veda. 2.12.3)

yō hatvāhimariṇāta sapta sindhūna yō gā udājadapadhā valasya | yō aśmanōrantaragniṁ jajāna saṁvr̥k samatsu sa janāsa indraḥ || (Rig. Veda. 2.12.3)

Summary : He who killed the himarina to free the sapta sindhu (seven rivers) and brought out the cows from the caves of Vala. He who brought forth Agni from two stones, know that he is Indra.

शक्रः || Shakra

Indra is called as शक्रः Shakra meaning शक्नोति दैत्यान् नाशयितुम् (Shabdakalpadhruma) one who is capable of destroying the Daityas or Rakshasas.

इन्द्रो यातूनामभवत्पराशरो हविर्मथीनामभ्या विवासताम् | अभीदु शक्रः परशुर्यथा वनं पात्रेव भिन्दन्त्सत एति रक्षसः || (Rig Veda 7.104.21)

indrō yātūnāmabhavatparāśarō havirmathīnāmabhyā vivāsatām | abhīdu śakraḥ paraśuryathā vanaṁ pātrēva bhindantsata ēti rakṣasaḥ || (Rig Veda 7.104.21)

Meaning : Indra is the destroyer, like the Paraashara, of those Rakshasas that harm the हविर्मथीनाम् who offer havishya (by performing yagnas), just like the परशु (axe) that destroys the forest is capable of smashing the earthen vessels. Rig Veda describes the strength and valor of Indra and the faith of Devatas in his might, in the following mantra

नहि नु यादधीमसीन्द्रं को वीर्या परः | तस्मिन्नृम्णमुत क्रतुं देवा ओजांसि सं दधुरर्चन्ननु स्वराज्यम् || (Rig. Veda. 1.80.15)

nahi nu yādadhīmasīndraṁ ko vīryā paraḥ | tasminnr̥mṇamuta kratuṁ devā ojāṁsi saṁ dadhurarcannanu svarājyam || (Rig. Veda. 1.80.15)

Meaning : For the Devas know no other person in their knowledge, who have surpassed Indra, in strength. In him the deities have placed their courage, wisdom, valor and prowess.  

मरुत्वान् || Marutvaan

इन्द्रः Indra is called as Marutvaan, meaning मरुतो देवाः पालनीयत्वेन (Shabdakalpadhruma) because he rules the Marut devatas. Maruts are 49 in number and they are the children of Diti, the mother of Daityas. At the loss of her children in the war between devatas and asuras, Diti prays to her husband Kashyapa to grant her a son who can slay Indra, the son of Aditi.

अकृत्वा पादयो: शौचं दिति: शयनमाविशत् | निद्रां चाहारयामास तस्या: कुक्षिं प्रविश्य स: ||३७ (Vish. Pura. Chap 21. 37)

वज्रपाणिर्महागर्भं चिच्छेदाथ स सप्तधा | सम्पीड्यमानो वज्रेण स रुरोदातिदारुणम् ||३८ (Vish. Pura. Chap 21. 38)

मा रोदीरिति तं शक्र: पुन:पुनरभाषत | सोऽभवत्सप्तधा गर्भस्तमिंद्र: कुपित: पुन: || ३९ (Vish. Pura. Chap 21. 39)

This famous legend given in Vishnupurana (Part 1, Chap 21, Slokas 30 to 41) recounts how Indra, goes to serve Diti, when she was pregnant with a son who is capable of killing him. Her hundred years of penance gets disturbed when she falls asleep without washing her feet. Taking this impious opportunity, Indra enters her womb and cuts the embryo within into seven pieces, with his Vajraayudha. As the child is began to cry, Indra asked it not to cry by saying "Maa Ruda ". So repeatedly saying he cuts each of them onto seven pieces, thus generating 49 pieces. Upon Diti's request of making them subservient to him, Indra refrains from destroying them. Thus, they are 49 Marutgana, who became the assistants of Indra in the form of "vaayuskanda" of Indra. (Also referred in Bhāgavata-purāṇa VI. 18. 19, 23-77: VIII. 13. 4: Brahmāṇḍa-purāṇa III. 5. 79, 90, 99, 104: Matsya-purāṇa 6. 47; 163. 22-3).

लोकपालकः || Lokapalaka

Rig Veda mantra 2.12.2 explains that Indra rules over the worlds, including Antariksha and Vyoma and without Indra there is no stability for any planet.  

यः पृथवीं व्यथमानाम दृंहद् यः पर्वतान प्रकुपिताँ अरम्णात् | यो अन्तरिक्षं विममे वरीयो यो दयामस्तभ्नात् स जनास इन्द्रः || (Rig. Veda. 2.12.2)

yaḥ parthivīṁ vyathamānāma dr̥ṁhad yaḥ parvatān prakupitām̐ aramṇāt | yō antarikṣaṁ vimamē varīyō yō dayāmastabhnāt sa janāsa indraḥ || (Rig. Veda. 2.12.2)

Summary : He who gave relief to the earth from distress, one who laid at rest the mountains (from flying), who supported the heavens, know that he is Indra.

रक्षकः || Rakshaka

Shrimad Bhagavad Gita states “paritranaya sadhunam vinasa ya ca dushkirtam” about protecting the sadhus and destroying the demons. Similarly, Indra is glorified in many mantras of Rig Veda, for his might and strength to protect all from Dasyus, Asuras and Rakshasas. Indra fights many asuras namely, Vritra, Namuchi, Sushnaha, Sambhara, Thuni, Chumuri, Varchi.

स वज्रभृद् दस्युहा भीम उग्रः सहस्रचेताः शतनीथ ऋभ्वा | चम्रीषो न शवसा पाञ्चजन्यो मरुत्वान् नो भवत्विन्द्र ऊती || (Rig. Veda. 1.100.12)

sa vajrabhr̥d dasyuhā bhīma ugraḥ sahasracētāḥ śatanītha r̥bhvā | camrīṣō na śavasā pāñcajanyō marutvān nō bhavatvindra ūtī || (Rig. Veda. 1.100.12)

Summary: Mighty, fierce, destroyer of Dasyus (asuras) using his Vajra, boundless with knowledge and prayed for by many, May Indra protect us.

गोत्रभित् || Gotrabhit

Indra is glorified for protecting the cows from the Panis with the help of Angirasa and Sarama. Rig Veda mantra 2.12.3 describes that Indra brought the cows out of the mountains of Vala.

इन्द्रस्याङगिरसां चेष्टौ विदत् सरमा तनयाय धासिम् | बृहस्पतिर्भिनदद्रिं विदद् गाः समुस्रियाभिर्वावशन्त नरः || (Rig Veda 1.62.3)

indrasyāṅagirasāṁ cēṣṭau vidat saramā tanayāya dhāsim | br̥haspatirbhinadadriṁ vidad gāḥ samusriyābhirvāvaśanta naraḥ || (Rig Veda 1.62.3)

Meaning: Indra and Angirasa rushi provided for the offspring of Sarama as desired and Brihaspati broke open the mountain and Sarama found the cows, bringing delight to people.

The story of Gograhana or the stealing of cows by Panis is given in the Rig Veda mantras of Mandala 10 (10.108.1 to 22).

इन्द्रदेवतास्वरुपम् || Indra Devata Swaroopam

Birth and Family

Indra descended from Mahavishnu in the following order according to Puranic Encyclopedia : Vishnu - Brahma - Marichi - Kaasyapa - Indra.

• Indra is the son of Kashyapa rishi ( son of Mariichi, the eldest of Brahma's manasaputras) and Aditi, the eldest daughter of Daksha. Aditi had 12 sons (Dvadasa Adityas) and another 21 sons the eldest of whom is Indra. Thus, devatas who originated from Aditi are 33 in number.
• Indra wields a lightning thunderbolt known as Vajraayudha. He rides on a white elephant known as Airavata. His horse's name is Uchchaihshravas|Uchchaihshrava.
• Sachi or Indrani, Pulomaja is the consort of Indra, Jayanta is the son and Devasena is the daughter of Indra. Devasena is the wife of Subrahmanya, son of Maheshwara.

वृत्रहा || Vrttraha

There are more than 250 Rig veda suktas that glorify Indra. Indra as the protector of his position and as the protector of devas, rishis, yagnas and cattle, is constantly engaged in battles with various asuras who throw obstacles in the performance of yagnas. Rig veda glorifies Indra for the slaying of one such asura namely Vrttrasura.  

वृत्रासुरजननम् || Vrttrasura Jananam  

There are two versions about the birth of Vrtraasura as given in Puranic Encyclopedia (Page 883).  

• According to Padma purana (Bhumi Kaanda, Chap 23), Hiranyakasipu, the son of Kashyapa Prajapati and his wife Danu, is killed by Mahavishnu for his wrong asuric deeds. Kashyapa grants her another powerful son Vala or Bala, whom Indra kills with his Vajraayudha for stealing the cows. Angered Kashyapa plucked a hair and made a burnt offering of it, saying that a son would be born who will be the destroyer of Indra.  

• According to Devi Bhagavata (Skanda 6) त्वष्ट्रा ॥ Tvasthra angered by Indra's killing of his son विश्वरूप || Vishwaroopa (also called Trisiras), initiates an आभिचारिकं यागं || aabhaicharikam yagam (a yagam performed to cause harm to an intended person) to procure a son to kill Indra.  

The ऋत्विज || ritvijas were to utter the mantra "इन्द्रशत्रुर्वर्धस्व" with अन्त उदात्तः ॥ Anta Udaatta or Udaatta swara in the end of the mantra (to mean Prosper Oh ! Enemy of Indra) instead they used the आद्य उदात्तः ॥ Aadya Udaatta swara in the beginning of the mantra (meaning Oh! Indra, one who has enemies, Prosper). The meaning of the mantra changed with the improper utterance of the swara. So instead of asking for the rise and prosperity of a son to take revenge on Indra, the ऋत्विज || ritvijas asked for the prosperity and glory of Indra who destroyed असुर || Asuras. Thus वृत्रासुर || Vrttrasura the son of त्वष्ट्रा ॥ Tvasthra was born, an enemy of Indra, but eventually Indra was rewarded with glory in killing वृत्रासुर || Vrttrasura. 

वृत्रासुरवध || Vrtrasura Vadha  

The Rig Veda sukta 1.80.1-16 describes the war of Indra against Vrttrasura. Indra's power and strength in wielding the Vajraayudha is beautifully described in these mantras.   

Under the leadership of Vrttrasura, his followers the Kaalakeyas and other rakshasas besieged the Devatas. The battle raged for a long time but Vrttra was invincible. Devatas along with Indra approach Mahavishnu for a solution to kill Vrttraasura. Mahavishnu informs them that Vrttra can be killed only with the bone of Dadhichi rushi. Thereby from the bones of Dadichi rushi, Indra prepares his weapon called "Vajra", and with a fatal stroke of Vajra, Vrttra falls dead. Hence Indra gets the name वृत्रहा || Vrttraha. (Mahabharata. Vana Parva. Chap 101, Verses 14, 15. Santi Parva. Chap 281. Verses 13 -21)   

By killing Vrttrasura, Indra incurred the sin of Brahmahatya. He goes to the Maanasasarovara to expiate for the sin. It was at that time that King Nahusha, takes the place of Indra. Cursed by Agastya rushi, Nahusha becomes a serpent and goes back to earth, then the Devatas reinstate Indra as Lokapalaka. (Mahabharata Udyoga parva Chap. 18). According to Valmiki Ramayana (Balakanda 24 Sarga), Devatas take Indra to Sarayu river for a holy bath to expiate the sin of Brahmahatya.   

Indra and Mountains

Valmiki Ramayana, Sundarakanda, gives the story of Indra cutting off the wings of mountains with his Vajraayudha. Mainaka, is the mountain that stands at the entrance of Patalaloka (पाताळस्याप्रमेयस्य द्वारमावृत्य तिष्ठसि | Valm. Rama. 5.1.93) guarding against the entrance and rise of the asuras. Upon being urged by Samudra, Mainaka raises himself to offer supporting place to Hanuman, who started his journey across the ocean to reach Lanka. In this context, Mainaka describes, the story of presence of winged mountains in Kritayuga.

पूर्वं कृतयुगे तात पर्वताः पक्षिणोऽभवन् | ते हि जग्मुर्दिशः सर्वा गरुडानिलवेगिनः || (Valm. Rama. 5.1.123)

Meaning : In the past, in Kritayuga, mountains, having wings, used to fly at great speeds, all over, like Garuda and Vaayu.

ततस्तेषु प्रयातेषु देवसंघः सहर्षिभिः | भूतानि च भयं जग्मुस्तेषां पतनशङ्कया || (Valm. Rama. 5.1.124)

Meaning : When they were so freely flying in all directions, the devas, and other living beings along with Rishis, doubted and feared that these mountains would fall on them.

ततः क्रुद्धः सहस्राक्षः पर्वतानां शतक्रतुः | पक्षान् चिच्छेद वज्रेण तत्र तत्र सहस्रशः || (Valm. Rama. 5.1.125)

Meaning : Angered by that, the thousand-eyed Indra chopped off wings of hundreds of mountains, then and there, using his Vajraayudha.

Agastya Rushi and Indra:

Once, Agastya rushi offered the havishya or oblation to Maruta which was meant for Indra.  When Indra came to know, he became distressed, as given in the following mantras of Rig Veda  

न नूनमस्ति नो श्वः कस्तद् वेद यदद्भुतम् | अन्यस्य चित्तमभि संचरेण्यमुताधीतं वि नश्यति || (Rig Veda 1.170.1)

na nūnamasti nō śvaḥ kastad vēda yadadbhutam | anyasya cittamabhi saṁcarēṇyamutādhītaṁ vi naśyati || (Rig Veda 1.170.1)

Summary : Indra says “Oh Agastya no one understands what happens in the present or future. Man’s mind is wavering. How can he understand wisdom with such mind? But you, who are man of wisdom and full of Vedic knowledge, if your intelligence gets disturbed what to speak of others?” 

किं न इन्द्र जिघांससि भ्रातरो मरुतस्तव | तेभिः कल्पस्व साधुया मा नः समरणे वधीः || (Rig Veda 1.170.2)

kiṁ na indra jighāṁsasi bhrātarō marutastava | tēbhiḥ kalpasva sādhuyā mā naḥ samaraṇē vadhīḥ || (Rig Veda 1.170.2)

Summary : Agastya rushi requests, “hey Indra, are you not the brother of Marutas, if I offer to Marutas, does it not go to you? If we do not offer then it’s your responsibility to give all that bhoga, it’s your responsibility. Therefore we are not at fault, you please share the oblation with marutas, justly. Do not harm us just like you have power to harm demons.” 

किं नो भ्रातरगस्त्य सखा सन्नति मन्यसे | विद्मा हि ते यथा मनोऽस्मभ्यमिन्न दित्ससि || (Rig Veda 1.170.3)

kiṁ nō bhrātaragastya sakhā sannati manyasē | vidmā hi tē yathā manō'smabhyaminna ditsasi || (Rig Veda 1.170.3)

Indra answers: “Oh my dear brother Agastya, you are my friend for long time. Why are you neglecting us? Your nature of mind is known. You do not have the desire to give oblation to us”  

अरं कर्ण्वन्तु वेदिं समग्निमिन्धतां पुरः | तत्रामृतस्य चेतनं यज्ञं ते तनवावहै || (Rig Veda 1.170.4)

araṁ karṇvantu vēdiṁ samagnimindhatāṁ puraḥ | tatrāmr̥tasya cētanaṁ yajñaṁ tē tanavāvahai || (Rig Veda 1.170.4)

Agastya recognizes Indra’s piercing and touching answer and the altar to offer yagna to Indra is prepared with समिधः samidha a special kind of wood. The blazing fire of yagna indicates the nectar or in one sense which rekindles the knowledge. 

तवमीशिषे वसुपते वसूनां तवं मित्राणां मित्रपते धेष्ठः | इन्द्र त्वं मरुद्भिः सं वदस्वाध प्राशान ऋतुथा हवींषि || (Rig Veda 1.170.5)

tavamīśiṣē vasupatē vasūnāṁ tavaṁ mitrāṇāṁ mitrapatē dhēṣṭhaḥ | indra tvaṁ marudbhiḥ saṁ vadasvādha prāśāna r̥tuthā havīṁṣi || (Rig Veda 1.170.5)

Summary : “Oh Indra! You are the master of wealth and treasures, you are the master of the Mitra and supporter of Mitra.  Oh Indra please be kind to the Marut devathas and accept the havishya of those yajnas that are performed in different seasons and be satisfied." 

Indra in Mahabharata

Many anecdotes are described in Mahabharata about Indra involved in various events in this great epic. Mahabharata is the treasure of references of events that happened in the eons prior to Mahabharata.

गोवर्धनः || Govardhana

Shrimad Bhaagavatam illustrates the subjugation of Indra's pride as in the story of Govardhana hill where Bhagavan Shri Krishna carried the hill and protected his devotees when Indra, angered by gopalas not worshiping him, launched torrential rains over the village.

अर्जुनः || Arjuna

Kunti, Pandu's wife had received a mantra from Durvasa rushi for begetting sons through devatas. Invoking Indra, Kunti begets a son named Arjuna. (Maha. Adiparva. Chap. 123).

कर्णः || Karna

On a day towards the end of his training Karna (in the guise of a brahmana) offers Parashurama his lap to rest his head and nap. But while Parashurama was asleep, Indra in the form of a bee stung Karna's thigh and despite the pain, Karna did not move, so as not to disturb his guru's sleep.

Indra afraid of the fighting skills of Karna took the form of a bee and stung Karna's thigh in order to benefit his son Arjuna. With blood oozing from his wound, it was revealed to Parashurama that Karna was not a brahmana, and so cursed Karna that he would forget all the mantras required to wield the divine weapon Brahmaastra, at the moment of his greatest need. Later this incident saved the life of Indra's son Arjuna from certain death.

Indra, king of the gods, asks in charity Karna’s natural armor 'Kavach and Kundal'. Karna donates this leaving himself vulnerable. (Maha. Aranyaparva. Chap 44, verse 9).

खाण्डववनदहनम् || Khandava Dahana

In Mahabharata (Adi Parva. Khandava daha parva Chap. 221 to 226), there is a legend about Agni who suffered from stomach ailments (due to the Yagnas of Svetaki King) was advised to consume the Khandava forest which contains the medicinal herbs that can treat his condition. In the process, Indra protects Takshaka who resides in the same forest, thus preventing Agni from consuming the medicinal plants.

In this parva, Krishna and Arjuna, are requested by Agni (who in the guise of a Brahmana) to quench his hunger. Realizing his true form, they agree to prevent his obstacles (Indra from sending heavy rain) in consuming the forest. Thus ensues a battle between Arjuna and Indra (father of Arjuna).

Indra in Ramayana

Although the legend of Ahalya and Indra happened in a different yuga, this anecdote is recounted by Viswamitra rushi to Shri Ramachandra and Lakshmana, in the Bala kanda, on his way to Mithila.

अहल्य || Ahalya

There are different versions of how Ahalya, the wife of Gautama rushi, was cursed to become a "stone" in different puranas. However, according to Valmiki Ramayana, Indra tricked Ahalya, when Gautama rushi went out for bath by taking his form. Gautama punished Indra with a curse of losing his manliness and Ahalya too was cursed of being invisible to the eyes of everyone, to take the form of a stone. He declared that her original form would return when Shri Ramachandra touched the stone. Indra's testicles were replaced with testicles of goat. (Val. Rama. Bala kanda)

हनुमान् || Hanuman

Vaayuputra, commanly called as Hanuman, in his younger days sprang up to Surya, mistaking it for a fruit to eat. Ascending towards the Devaloka he sees Airavata, the vahana of Indra and goes towards it to swallow it. Seeing the tussle between Maruti and Airavata. feeling threatened Indra uses his weapon Vajraayudha to cut the " hanu" (jaw bones) of Maruti and he falls dead on earth. Vaayu, grieving the loss of his son, takes him to Patalaloka, where Brahma and other devatas console him and revive Maruti. As the "hanu" was cut by Indra's vajra, Maruti gets the name of "Hanuman". Indra also blesses him to be a chiranjeeva and would die only when he wished so. (Uttara Ramayana, Valmiki Ramayana, Kishkindha Kanda, 66th Sarga).

इन्द्रजित् || Indrajit

Ravana asura conquered the world with Brahma's blessing. His son Meghanadha, defeated Indra in a fierce battle and took him to Lanka as a prisoner. Upon Brahma's intervention, he was released. Thus, Meghanadha got the title of Indrajit, one who gained victory over Indra (Uttara Ramayana).

Indra as a Position

Devi Bhagavata 3rd, 5th and 9th Skandas describe the time period or kalamana of celestial beings such as Brahma, Vishnu and Maheshwara. As given in Puranic Encyclopedia (Page 326, 372) there are 14 मन्वन्तराः || Manvantaras during the life of Brahma, and each Manvantara will have its own Manu, Indra and Devatas. Thus 14 Manvantaras make a कल्पः || Kalpa which corresponds to a day in the life of Brahma. Since in every Manvantara one Indra changes, 14 manvantaras will have 14 different Indras.

Vishnupurana Part 1. Adhyaya 3, describes the Kalamana differently. According to it one thousand chaturyugas form one day of Brahma and it has 14 Manus.

The following list of Manus and Indras of one Kalpa given in Vishnupurana.

Manvatara/Manu	Indra
Svayambhuva	Yajna (Avatar of Vishnu)
Swarochisha	Vipaschit
Uttama	Sushaanti
Taamasa	Shibi
Raivata	Vibhu
Chaakshusha	Manojava
Vaivasvata	Purandara (the present Indra)
Savarni	Bali
Daksha Saavarni	Adbhuta
Brahma Saavarni	Shanti
Dharma Saavarni	Vish
Rudra Saavarni	Ritudhaama
Rauchyadeva Saavarni (Ruci)	Divaspati
Indra Saavarni (Bhaumi)	Suchi

Additional Information

The following Rig Veda mantras (2.12.1 to 15) describe the greatness of Indra.

यो जात एव प्रथमो मनस्वान् देवो देवान् क्रतुना पर्यभूषत् | यस्य शुष्माद् रोदसी अभ्यसेतां नृम्णस्य मह्ना स जनास इन्द्रः || 1

yō jāta ēva prathamō manasvān dēvō dēvān kratunā paryabhūṣat | yasya śuṣmād rōdasī abhyasētāṁ nr̥mṇasya mahnā sa janāsa indraḥ || 1

Summary : As soon as he was born, who was decorated as the Chief of Devas, know that he is Indra.

यः पर्थिवीं व्यथमानाम दृंहद् यः पर्वतान् प्रकुपिताँ अरम्णात् | यो अन्तरिक्षं विममे वरीयो यो दयामस्तभ्नात् स जनास इन्द्रः || 2

yaḥ parthivīṁ vyathamānāma dr̥ṁhad yaḥ parvatān prakupitām̐ aramṇāt | yō antarikṣaṁ vimamē varīyō yō dayāmastabhnāt sa janāsa indraḥ || 2

Summary : He who gave relief to the earth from distress, one who laid at rest the mountains (from flying), who supported the heavens, know that he is Indra.

यो हत्वाहिमरिणात सप्त सिन्धून् यो गा उदाजदपधा वलस्य | यो अश्मनोरन्तरग्निं जजान संवृक् समत्सु स जनास इन्द्रः || 3

yō hatvāhimariṇāta sapta sindhūna yō gā udājadapadhā valasya | yō aśmanōrantaragniṁ jajāna saṁvr̥k samatsu sa janāsa indraḥ || 3

Summary : He who killed the himarina to free the sapta sindhu (seven rivers) and brought out the cows from the caves of Vala. He who brought forth Agni from two stones, know that he is Indra. येनेमा विश्वा च्यवना कृतानि यो दासं वर्णमधरंगुहाकः | श्वघ्नीव यो जिगीवाँ लक्षमाददर्यः पुष्टानि स जनास इन्द्रः || 4

यं स्मा पृच्छन्ति कुह सेति घोरमुतेमाहुर्नैषो अस्तीत्येनम् | सो अर्यः पुष्तीर्विज इवा मिनाति श्रदस्मै धत्त स जनास इन्द्रः || 5

यो रध्रस्य चोदिता यः कृशस्य यो ब्रह्मणो नाधमानस्य कीरेः | युक्तग्राव्णो योऽविता सुशिप्रः सुतसोमस्य स जनास इन्द्रः || 6

यस्याश्वासः प्रदिशि यस्य गावो यस्य ग्रामा यस्य विश्वे रथासः | यः सूर्यं य उषसं जजान यो अपां नेता स जनास इन्द्रः || 7

Summary : He under whose control the horses, cattle, villages, and chariots exist, He who brought out Surya and Ushas (dawn), who leads the waters, know that he is Indra.

यं क्रन्दसी संयती विह्वयेते परेऽवर उभया अमित्राः | समानं चिद् रथमातस्थिवांसा नाना हवेते स जनास इन्द्रः || 8

यस्मान्न ऋते विजयन्ते जनासो यं युध्यमाना अवसे हवन्ते | यो विश्वस्य प्रतिमानं बभूव यो अच्युतच्युत् स जनास इन्द्रः || 9

यः शश्वतो मह्येनो दधानानमन्यमानाञ्छर्वा जघान | यः शर्धते नानुददाति शृध्यां यो दस्योर्हन्ता स जनास इन्द्रः || 10

यः शम्बरं पर्वतेषु क्षियन्तं चत्वारिंश्यां शरद्यन्वविन्दत् | ओजायमानं यो अहिं जघान दानुं शयानं स जनास इन्द्रः || 11

यः सप्तरश्मिर्वृषभस्तुविष्मानवासृजत् सर्तवे सप्तसिन्धून् | यो रौहिणमस्फुरद् वज्रबाहुर्द्यामारोहन्तं स जनास इन्द्रः || 12

दयावा चिदस्मै पृथवी नमेते शुष्माच्चिदस्य पर्वता भयन्ते | यः सोमपा निचितो वज्रबाहुर्यो वज्रहस्तः स जनास इन्द्रः || 13

यः सुन्वन्तमवति यः पचन्तं यः शंसन्तं यः शशमानमूती | यस्य ब्रह्म वर्धनं यस्य सोमो यस्येदं राधः स जनास इन्द्रः || 14

यः सुन्वते पचते दुध्र आ चिद वाजं दर्दर्षि स किलासि सत्यः | वयं त इन्द्र विश्वह परियासः सुवीरासो विदथमा वदेम || 15

The following slokas from Vishnupurana (Part 1, Adhyaya 21, Slokas 30 to 41) describe Indra's attempt to destroy the unborn child of Diti and thereby creation of Marutganas.

दितिर्विनष्टपुत्रा वै तोषयामास काश्यपम् | तया चाराधित: सम्यक्काश्यस्तपतां वर: || ३०

वरेण च्छन्दयामास सा च वव्रे ततो वरम् | पुत्रमिन्द्रवधार्थाय समर्थममितौजसम् || ३१

स च तस्मै वरं प्रादाभ्दार्यायै मुनिसत्तम: | दत्वा च वरमत्युग्रं कश्यपस्तामुवाच ह || ३२

शक्रं पुत्रो निहन्ता ते यदि गर्भं शरच्छतम् |समाहितातिप्रयता शौचिनी धारयिष्यसि ||३३

इत्येवमुक्त्वा तां देवीं संगत: कश्यपो मुनि: | दधार सा च तं गर्भं सम्यक्छोचसमन्विता ||३४

गर्भमात्मवधार्थाय ज्ञात्वा तं मघवानपि | शुश्रूषुस्तामथागच्छद्विनयादमराधिप: ||३५

तस्याश्चैवान्तरप्रेप्सुरतिष्ठत्पाकशासन: | ऊने वर्षशते चास्या ददर्शान्तरमात्मना ||३६

अकृत्वा पादयो: शौचं दिति: शयनमाविशत् | निद्रां चाहारयामास तस्या: कुक्षिं प्रविश्य स: ||३७

वज्रपाणिर्महागर्भं चिच्छेदाथ स सप्तधा | सम्पीड्यमानो वज्रेण स रुरोदातिदारुणम् ||३८

मा रोदीरिति तं शक्र: पुन:पुनरभाषत | सोऽभवत्सप्तधा गर्भस्तमिंद्र: कुपित: पुन: || ३९

एकैकं सप्तधा चक्रे वज्रेणारिविदारिणा | मरुतो नाम देवास्ते बभूवुरतिवेगिन: ||४०

यदुक्तं वै भगवता तेनैव मरुतोऽभवन् | देवा एकोनपञचाशत्सहाया वज्रपाणिन: ||४१

References

1. Amarakosha Reference : http://www.sanskritebooks.org/2009/07/amara-kosa-the-sanskrit-thesaurus-with-notes-index/ (Page no 9 and 10 )
2. Indra cut off the wings of mountains :http://valmikiramayan.net/utf8/sundara/sarga1/sundara_1_frame.htm
3. Origin of Marutganas : www.vcscsd.org/content/balabhavan/18-Puranas.pdf
4. http://ignca.nic.in/Vedic_portal_rigveda_shakala_Samhita_m01.htm Indra Suktas as given in Vedic Heritage portal.
5. Puranic Encyclopedia link https://ia802606.us.archive.org/17/items/puranicencyclopa00maniuoft/puranicencyclopa00maniuoft.pdf
6. Vishnupurana link : http://www.astrojyoti.com/puranassanskrit.htm