Sowmya Narayana Perumal temple

Shrines in the temple

Hiranyakshipu, the demon king, got arrogant after he got boons from Brahma, which nearly made him invincible. He troubled the Devas (celestial deities) and they prayed to Vishnu for rescue. Vishnu was ready to take the Narasimha avatar to slay the demon king. The Devas pleaded with Vishnu to show the form before he could take it. Vishnu showed them the avatar, but not pleased with the vision, the Devas and sages pleaded him to show it again. Vishnu appeared in three forms of standing, sitting and resting posture at Thirukoshtiur. Since Vishnu showed his form after hardship (called Thirukkai in Tamil) of Devas, the place came to be known as Thirukoshtiur.[2]

Temple tank outside the temple

Sowmyanarayana Perumal temple covers an area of about 2 acres (0.81 hectares) and has a five-tiered gopuram (gateway tower). The temple in enclosed in a rectangular enclosure with huge granite walls. The central shrine houses the image of the presiding deity, Uragamellayan Perumal in reclining posture on a snake bed similar to that of Srirangam Ranganathaswamy temple. The images of Sridevi and Bhudevi are also housed in the sanctum. There two life size images of Narasimha, the avatar of Vishnu. One of them is shown holding the demon Hiranyakshipu and other slaying him. Though it is a Vishnu temple, the temple has image of Shiva in the form of Lingam, Vinayaka and Subramanya.[3] The festival deity is named Sowmya Narayana Perumal made of panchaloha.

The vimana, the shrine over the sanctum is Ashtanga in architecture, which has eight parts, namely, Adhistana (base), three Padas (struct), Prashthana (limb), Griva (leading struct), Shikara (cylindrical holder) and Stupi (top portion). The outer parts of the vimana has various stucco images of Narasimha, sages, Dasavatara and other mythical stories. The Ashtanga Vimana is found in only three places, namely, the Uthiramerur, Koodal Azhagar Temple and Cheranmadevi temples.[4] The ashtanga vimana raising to a height of 25 m (82 ft), is taller than the gopuram of the temple, which is not a common feature in Dravidian temples.[2]

The shrine of the consort of Sowmyanarayana Perumal, Thirumamagal, is located to the south of the main shrine. There are smaller shrines of Lakshmi Narasimha, Rama, Lakshmi Narayana and Krishna located close to the sanctum. The shrines of Andal, Narasimha and Manavala Mamunigal are found in separate shrines around the first precinct. The shrines of Garuda, Anjaneya, Ramanuja, Vedanta Desika and Azhwars are found in the second precinct.[2] According to historian K.V. Soundararajan, the Rangantha temples in South India built during the 9th and 10th centuries have a systematic arrangement of subsidiary deities as seen in this temple along with the Appakkudathaan Perumal Temple at Koviladi, Veeraraghava Perumal temple at Thiruvallur, Rajagopalaswamy temple at Mannargudi and Rangantha temple at Srirangapatna.[5]

Ramanuja, the preceptor of Vaishnavadatta philosophy, revealed the gospel of Ashtakshara to the world in the temple

Sowmyanarayana Perumal temple is revered in Nalayira Divya Prabhandam, the 7th–9th century Vaishnava canon, by Periazhwar, Thirumalisai Alvar Bhoothathazhwar and Peyazhwar. The temple is classified as a Divyadesam, one of the 108 Vishnu temples that are mentioned in the book. During the 18th and 19th centuries, the temple finds mention in several works like 108 Tirupathi Anthathi by Divya Kavi Pillai Perumal Aiyangar.[4]

The temple is known as the place where Ramanuja, the expounder of Vaishnavadatta philosophy preached the holy ashtakshra "Ohm Namo Narayana" to all people irrespective of their caste. The place was the birthplace of Thirukoshtiyur Nambigal, the teacher of Ramanuja and who taught him the gospel and instructed him not to reveal it to anyone.[6] Taking the risk of his life, Ramanjua climbed up the temple and revealed the verse to the whole world. Nambigal was pleased by the spirit of Ramanuja and named him Emperumanar (meaning my superior). Following the event, a life size image of Ramanuja was housed in the Ashtanga Mandap of the temple.[3]

The temple follows the traditions of the Thenkalai sect of Vaishnavite tradition and follows Vaikasana aagama. In modern times, the temple priests perform the pooja (rituals) during festivals and on a daily basis. As at other Vishnu temples of Tamil Nadu, the priests belong to the Vaishnavaite community, a Brahmin sub-caste. Six daily rituals are held at various times of the day and many yearly festivals are held at the temple, of which the float festival during the Tamil month of Masi (February–March), Navrathri during September–October and Vaikunta Ekadasi during Margazhi (December–January) being the most prominent. There are weekly, monthly and fortnightly rituals performed in the temple.[2]