Iyengars (also spelt Ayyangar or Aiyengar, pronounced ɐjːɐŋɡaːr) are an ethnoreligious community of Tamil-speaking Hindu Brahmins, whose members follow Sri Vaishnavism and the Visishtadvaita philosophy propounded by Ramanuja. Found mostly in the Southern Indian states of Tamil Nadu, Karnataka, and Andhra Pradesh, Iyengars are divided into two denominations, the Vadakalai and the Tenkalai. The community belongs to the Pancha Dravida Brahmana classification of Brahmins in India.
There are several opinions regarding the etymology of the term Iyengar, which is the anglicized form of the Dravidian word Aiyaṅgār (ஐயங்கார், əjəŋɡɑːɾ).
One is that it derives from the Proto-Dravidian word ayya-gāru (𑀅𑀬𑀕𑀭𑀼), which became Ayyangāru (அய்யங்காரு), and later Ayengar. The term ayya is the Tamil equivalent of the Sanskrit word ārya, (𑀆𑀭𑁆𑀬/आर्य) which in Sanskrit means noble. Gāru refers to a form of the Pali term gārava, and later gaurava, meaning respect or esteem.
Another is that the word ayyangār was first used by Kandhādai Ramanuja Ayyangār of Tirupati, around 1450 AD.
The Iyengar community traces its philosophical origins to Nathamuni, the first Sri Vaishnava acharya, who lived around 900 CE. He is traditionally believed to have collected the 4,000 works of Nammalvar and other alvars, the poet-saints of Southern India who were intensely devoted to Vishnu on both an emotional and intellectual plane. The belief is that he set this collection - commonly called the Tamil Prabhandams - to music, and he introduced the devotional hymns of the alvars into worship, thus mixing their Tamil Veda with the traditional Vedas written in Sanskrit. A scriptural equivalence was accepted by the community that formed from his works. The Sanskrit texts are considered to be metaphysical truth and the Tamil oral variants to be based on human experience of the same. This community became immersed in the dual-language worship in temples where issues of varna were of no concern.
A century or so later, Ramanuja became the principal amongst religious leaders who formalized the efforts of Nathamuni as a theology.