While making offerings to the Ādityas (aditya) in Ṛgveda (Rigveda), Aṃśa has been mentioned as one of the many Ādityas — imā gira ādityebhyo ghṛitasnuḥ śṛiṇotu mitro/ aryamā bhago na stubijāto baruṇo dakṣo aṁśaḥ.

• Twelve ādityas were created after being cast from the mouth of Sun god Sūrya of Vivasvān— mukharāgaṁ tu yat pūrbat mārtaṇḍasya mukhacyutam.

Aṃśa is the foremost of these twelve solar gods.   [See Āditya]

• At the beginning of creation, the twelve gods collectively known as Jaya were cursed by Brahmā. They are born as twelve gods during every period reigned by a Manu. According to Purāṇas (Puranas), these gods, during the time of Vaivasvata Manu, were conceived in the womb of Kaśyapa Prajāpati’s (Kashyap Prajapati) wife Aditi, and born as the twelve Ādityas. Aṃśa is the foremost among these Ādityas.

• The names of the twelve Ādityas mentioned in Mahābhārata (Mahabharata), though slightly different from the one obtained from Purāṇas, also includes Aṃśa’s— bhago’ṁśaścāryamā caiba mitraḥ.

• When Kṛṣṇa (Krishna) and Arjuna were all prepared to set the Khāṇḍava (Khandaba) forest on fire, Indra arrived to hinder their efforts. A war broke out between the two sides. At this time, Aṃśa too had arrived to help Indra and it is noteworthy that his favorite weapon was Śakti (shakti; javelin) – aṃśastu śaktiṃ jagāha.

• On the day of the ceremony of Skanda Kārtikeya (Skanda Kartikeya) being appointed as the Commander-in-chief of the army of the Gods, Aṃśa too arrived along with the twelve Ādityas and Vivasvān with various articles that were needed for the ceremony— pūṣña bhagenāryamnā ca aṁśena ca bibasbatā.

Aṃśa also gave Skanda five of his vassals whose names are Parigha (Parigh), Vaṭa (Bat), Bhīma (Bhim), Dahati (Dahati) and Dahana (Dahan)— parighañca vaṭañcaiva bhīmañca sumahābalam/ dahatiṁ dahanañcaiva pracandau bīryasammatau/ aṁśo’pyanucarān pañca dadau skandāya dhīmate.

• According to modern day scholars, Aṃśa is a solar deity and the word Aṃśa is most likely similar to the word Aṃśu which means rays of the sun. It is perhaps for this reason that Purāṇas mention a demon called Aṃśa visible on the chariot carrying Sūrya during the month of Agrahāyaṇa (Aghrayana).