'The Immersed') were the Tamil poet-saints of South India who espoused bhakti (devotion) to the Hindu preserver deity Vishnu, in their songs of longing, ecstasy, and service.

The devotional outpourings of the Alvars, composed during the early medieval period of Tamil history, were the catalysts behind the Bhakti Movement through their hymns of worship to Vishnu and his avatars.

The poetry of the Alvars echoes bhakti to God through love, and in the ecstasy of such devotions they sang hundreds of songs which embodied both depth of feeling and the felicity of expressions.

The bhakti literature that sprang from Alvars has contributed to the establishment and sustenance of a culture that deviated from the Vedic religion and rooted itself in devotion as the only path for salvation.

[8] The Indologist Sudalaimuthu Palaniappan has established[9] from epigraphy and textual evidence that the traditional term Āḻvār (ஆழ்வார்) for Vaiṣṇavaite Tamil poet saints has historically been a corruption of the original Āḷvār (ஆள்வார்).

He states: "āḻvār is but a corrupt form of āḷvār which has been used interchangeably with nāyanār in secular and religious contexts in the Tamil land" and "...

The original word ஆள்வார் compares with the epithet 'Āṇḍãḷ' (ஆண்டாள்) for the female canonized Vaishnava saint Gōdai (கோதை) and they share the same verb Tamil.

In the course of time the term underwent the process of sound variation, took the form āḻvār and acquired the folk etymology which was accepted and fixed by the tradition.

[14][17] The legendary birth of the Alvars is traced to an event in the mid-Dvapara Yuga, due to a heated debate between Vishvakarma (the divine architect of the gods) and Agastya (a sage) about the superiority of the Sanskrit or the Tamil language.

[citation needed] Enraged, Vishvakarma curses Agastya in turn that his most favourite language (Tamil) would be tarnished in the future.

Vishnu decides that his amshas (parts of his identity) would be incarnated as humans on earth, and teach them the path of righteousness and devotion to him.

These amshas happily accepted their birth as the twelve Alvars, aligning with the boon given to Agastya, and also became a role model for the human beings who came later in the Kali Yuga.

The Alvar is now tentatively identified as Sthanu Ravi Kulasekhara (reigned c. 844/45–870/71 CE), the first known ruler of the medieval Cheras kings of Kerala.