Once Devendra came out victorious in a battle with a demon called Jambasura. Rejocing at his triumph and brimming with pride, he was making a processional return seated on his celestial white elephant "Iravata". At that moment, sage Durvasa greeted him with a garland of flowers and offered it to him as Goddess Lakshmi's prasadam. But to his dismay, Devendra not only received it with scant respect but used it only to adorn temple of his elephant. When the bees, hovering around the fragrant flowers, stung the elephant, it got irritated, pushed the garland, threw it on the ground, and trampled it under its feet. This incident incited further the sage Durvasa, noted for his temperamental weakness. So he cursed Indra that he would cease to enjoy the grace of Goddess Lakshmi forthwith. Immediately all his riches got submerged in the milky-ocean and Indra's dignity and prestige suffered a blow.

    The grief-stricken Indra surrendered to Lord Vishnu for the restoration of his status. Lord Vishnu suggested the milky ocean be churned for getting back the vanished riches. The devas and Asuras plunged into this venture jointly on an understanding that they would have an equal share of Amrutha the nectar, generated during the process. They used the mountain, Meru, as the churning-stick and the serpent, Vasuki, as the rope. At that time, Lord Vishnu took the form of a tortoise called Kachapa or Koorma and bore the mountain Meru on His back to prevent it from getting drowned.

    When the churning was in progress Vasuki, unable to withstand the continuous friction between its body and the rough moutain, ejected a dreadful poison called Halahala. The radiation of this poison darkened the body of Vishnu.

    The movement, of the Adi Koorma, unable to bear the Oppressive radiation, agitated the milky ocean violently Causing distress to all creatures sheltered therein. The Devas and Asuras too would have to run helter-skelter but for Lord Siva who restored calmness by consuming the deadly black poison. The halahal stopped in the neck of Lord Siva by the will of Goddess Gowri and remained as an ornament to the neck of Lord Siva. Hence Lord Siva came to be called Neelakanta thenceforth.

    Greatly relieved, the Devas and Asuras continued their task. They secured many valuables, which included the riches lost by Indra, nectar, Goddess Lakshmi, the Moon-and the precious gem, Kausthuba. The gods offered Lakshmi's hand in wedding to Lord Vishnu as a token of their gratitude and also presented Him the gem Kausthuba. As an atonement for causing, though not intentionally, distress to the creatures in the sea in the from of Kachapa Lord Vishnu wanted to have Prayaschitha or penance and came to Kanchipuram to worship Lord Siva as per the latter's counsel, Sri Kachapeswara.

    The temple has 3 prakaras with a north-facing tower. Just after the entrance to the temple, there is a sacred tank called Ishtasiddhi Theertham. It has four bathing ghats, each with a distinct power to reward the devotees having a dip there. Experience has substantiated the common belief that a holydip in this tank, especially on Sundays, ensures longevity of life with sound health. The Brahmostsavam at this temple is celebrated in the month of Chaitra.

    The other Shrines located in this temple are that of Shri Jambukewara, Arunachaleswara, Kalahastheeswara and Chidambareswarar, Subrahmanya, Saraswathi with eight arms Vishnu, Satyavachana Vinayaka and Durgra. Shri Narayan Seva Ashram is also nearer this temple.