Abhimanyu was the son born of the womb of Subhadrā, sister of Sāraṇa and Śrī Kṛṣṇa.

Varcā or Varcas, son of Candra (the Moon-God) was born as the son of Arjuna. In the Aṃśāvataraṇa adhyāya it is said that–
yastu varcā iti khyātaḥ somaputraḥ pratāpavān
so’bhimanyurvṛhat kīrtirarjunasya suto’bhavat.

His arms were long, breast wide, and eyes were stretched up to the ears. Abhimanyu grew up so heroic and warlike that the Vṛṣṇi-heroes like Sātyaki thought that they will kill the Kaurava(s), under the leadership of Abhimanyu, and until the Pāṇḍava’s period of exile was not over, Abhimanyu would rule the kingdom.

Abhimanyu learnt the art of weaponry from his father. While staying in Dvārakapuri, in his maternal uncle’s house, Abhimanyu also took lessons from Kṛṣṇa and Rukminī’s son, Pradyumna.

During the forest-exile of the Pāṇḍava(s), Abhimanyu was in Dvārakā. After the end of their exile and ajñātavāsa, Abhimanyu got married to Uttarā, daughter of King Virāṭ, of the kingdom of Matsya.

Before the battle commenced, in the context of describing the powers and qualities of the warriors belonging to the Pāṇḍava side, Bhīṣma was telling Duryodhana that as an opponent, Abhimanyu was equal to Arjuna and Vāsudeva. He was well-experienced in weaponry and their application-strategies. He was mindful and constant in determination. In front of Dhṛtarāṣṭra, Sañjaya was also saying that– the qualities predominant in the character of Kṛṣṇa and the Pāṇḍava(s) could also be found in Abhimanyu. He was like Yudhiṣṭhira in patience,
yudhiṣṭhirasya dhairyeṇa kṛṣṇa caritena ca
karmabhirbhīmasenasya sadṛśo bhīmakarmaṇaḥ.
dhananjayasya rūpeṇa vikrameṇa śrutena ca
vinayāt sahadevasya sadṛśo nakulasya ca.

Abhimanyu’s horses were of a copper-grey colour, and the dhvajā of his chariot was made of the flower of karṇikā, decked with gold.
jāmvūnadavicitreṇa karṇikāreṇa ketunā.

In Mahābhārata, in the battle of Kurukṣetra, Abhimanyu is often found to be engaged in fighting with many warriors. Abhimanyu helped Bhīmasena in fighting against Bhagadatta. Abhimanyu also fought valiantly against such great warriors as Droṇa, Bhīṣma, Śalya and the others. Abhimanyu also assisted Arjuna in the battle.

On the thirteenth day of the battle, as per the advice of Ācārya Droṇa, Duryodhana challenged Arjuna to fight the Saṃśaptaka(s). Called to fight them, Arjuna went away. At this opportunity, Droṇa formed a cakravyūha.

Karṇa, Duḥśāsana, Kṛpācārya, Duryodhana, Droṇācārya, Aśvatthāmā, Jayadratha– these seven rathī(s) (warriors who fight on chariots) were destroying the Pāṇḍava army from within the vyūūha. Considering Droṇa’s prowess and the impenetrability of cakravyūha, Yudhiṣṭhira asked Abhimanyu to penetrate it. Abhimanyu said, he has learnt from his father the strategy of penetrating cakravyūha, but he did not know how to get out out it–
droṇasya dṛḍhamatyugramanīkapravaraṃ yudhi
pitṛṇāṃ jayamākānṣannavagāhe’ vilamvitaṃ.
upadiṣṭo hi me pitāyogo’nīkaviśātane
notsahe tu vinirgantumahaṃ kasyañcidāpadi.

Yudhiṣṭhira and Bhīma assured Abhimanyu that they would follow him, if he could only make the entrance to the vyūha. When the charioteer of Abhimanyu was afraid to enter the vyūha, Abhimanyu instructed him to take the chariot towards Droṇa.

Assured by his elder uncle, Abhimanyu penetrated the vyūha with great enthusiasm. Droṇa, Kṛpa, karṇa, Aśvatthāmā, Vṛhadvala and Kṛtavarma – these six rathī(s) surrounded him. Abhimanyu also heroically resisted them. The warriors of the Kaurava side felt embarrased seeing his valour. Many soldiers were slain by him.

That day, Jayadratha became invincible by the boon of Mahādeva, and he was protecting the gateway. So, despite their best efforts, heroes like Bhīma, Sātyaki and Dhṛṣtadyumna could not enter into the vyūha.

Vṛhadvala, king of Kośala approached towards Abhimanyu, and the latter fought him heroically. At first, the flag bearing stand over Abhimanyu’s chariot was cut off by Vṛhadvala, and his charoiteer also fell down. Abhimanyu, in rage, attacked Vṛhadvala with nine arrows, and defeated him.

After Abhimanyu killed Rukmaratha, son of Śalya, the other rathī(s) of the Kaurava side started attacking Abhimanyu. Duryodhana’s son Lakṣmaṇa came to fight him, and Abhimanyu killed him, too. Furious to see his beloved son dead, Duryodhana ordered for Abhimanyu’s death–
tato duryodhanaḥ kruddhaḥ priye putre nipātite
hatainamiti cukrośa kṣatriyān kṣatriyarṣabhaḥ.

Droṇa, Kṛpa, Karṇa, Duryodhana, Duḥśāsana, Aśvatthāmā, Jayadratha– these seven great warriors attacked Abhimanyu together. They destroyed his chariot and charioteer, and also his armour, sword and bow were cut off. Fighting alone, Abhimanyu was getting exhausted. At this time, the son of Duḥśāsana gave a hard blow with his mace. Heavily wounded, Abhimanyu fell on the ground and died.

At the time of Abhimanyu’s death, his wife Uttarā was pregnant. Towards the end of the battle of Kurukṣetra, the Brahmāstra cast by Aśvatthāmā stopped the movement of the child in the womb of Uttarā.
During the Aśvamedha yajña performed by Yudhiṣṭhira, Uttarā gave birth to that dead child. By the grace of Kṛṣṇa, the dead chilsd was rejuvenated. This son of Abhimanyu and Uttarā was called Parīkṣit.

After his death, Abhimanyu went back to Candraloka, since he was a partial incarnation of varcā, son of Candra.