This is the very Deity which incarnated for giving light to Lord Brahma for performing yajna. The Lord is known as Deepa Prakashar. He is also known as Valakoli Perumal. Vallaka in Tamil means light and oli in tamil means effulgence.
Sri Deepa Prakasar Perumal Temple or Sri Vilakkoli Perumal is one among the 108 Divya Desams of Lord Vishnu. This temple is the 45th Divya Desam. [A Divya Desam is one of the 108 Vishnu temples that are revered by the 12 Azhwars (great saints) in the Divya Prabandha, a collection of 4,000 Tamil verses. Divya means “premium” and Desam indicates “place” (temple). Of the 108 temples, 105 are in India, one is in Nepal, and last two are outside the earthly realms. The Divya Desams are revered by the 12 Azhwars in the Divya Prabandha, a collection of 4,000 Tamil verses.]
The deity at Sri Deepa Prakasar Perumal temple is facing west direction. The temple is located in Vishnu Kanchi along with most other Vaishnava temples in Kanchipuram. The temple has a three-tiered rajagopuram, the gateway tower. The central shrine of the temple has the presiding deity, Deepaprakasar Perumal. There are shrines for Lakshmi Hayagriva, Andal, Vedanta Desika and Azhwars. The place is also known by the name Thoopul as it was dense with Dharba grass.
This is the birthplace of Sri Vedanta Desika (or Swami Desikan, Swami Vedanta Desikan, Thoopul Nigamaantha Desikan). Vedanta Desika (1268–1370) was one of the most brilliant stalwarts of Sri Vaishnavism in the post-Ramanuja period. He was an ardent devotee of Deepa Prakasar Temple at Thoppul. Sri Desikan is a gift to his mother who prayed to Lord seeking for a child. Responding to her prayer, Lord of Tirupati – Lord Venkatachalapathi Balaji asked the bell in His hand to be born as the son of the mother. For this reason, bell is not used during pujas in Tirupati Balaji temple after this event. He was an outstanding scholar of highest degree in the Vaishnava scriptures. He rendered a large number of Sanskrit works in Tamil. He has also authored in Tamil the Adaikala Pathu (Asylum 10) on Lord Varadaraja Perumal.
The Brahmostavam festival during the Tamil month of Puratasi (Sep – Oct) is the major festival celebrated in Vedanta Desika shrine. During the festival, the festival deity of Desika is carried to Sri Varadaraja Perumal Temple. Sri Vedanta Desika had unparalleled devotion to Lord Varadaraja Perumal which was evidently visible in one of his compositions Varadaraja Panchasat. He sung praising the glories of Lord in sacred fifty verses. During Brahmostavam, Lord Varadaraja pays visit to Thupool and resides here for three days. On Garuda seva day, Lord Varadaraja presents His garlands to Desika acarya and pays tribute to His fervent devotee. In this way Lord pays continuous visit and homage to His devotee during the Brahmostavam. Lord Varadaraja pays periodic visits to Thupool on the auspicious days of Chaitra Pournami and on the twelfth day after Vaikundha Ekadashi. The temple tank, Saraswathi Theertham, is located outside the premises. A shrine is dedicated to Vedanta Desika facing south is seen in the temple. Desika’s son Nayina Varadachari completed the construction of this temple.