Once there was a king named Swethan, the son of Thundu maran of the Surya dyansty. Fearing early death he sought the help of "Maruthuva Maharishi", the son of Lord Surya the sun god. He instructed swethan to chant the "Mrithyunjaya Manthiram" by sitting under the Tree vilvam which was on the south bank of the pushkarani. Lord Narayanan presented himself before the king and blessed him with a long life. This Kshetram is known as South Tirupathi. All the offering in due to the Thiruvenkadamudayan of Tirupathi can be offered here too.
At Thiruvinnagar, Lord Oppiliappan blesses along with godess Bhoodevi as an equivalent form of Lord varahaswamy and Bhoodevi as Tirumala Tirupathi. Also as an equivalent form of Lord Srinivasa and Padmavathi Thaayar, the Lord blesses us as Thiruvellakulam as Lord Srinivasa and Padmavathi.
As for the above stated reasons, both the Kshetrams are considered in equivalent with Tirumala Tirupathi. Sri Annanperumal is the elder brother of Lord Vendateswara of Thirumala. Hence, this temple is known as Annan Perumal Kovil As he saved the king Swethan from the death fear he shows himself as Varadharajan. So, the perumal stands as form representing all the yugams. the Vimaanam too has a hint of this act as Thathuva Yodhaga Vimaanam. Vellam means flood and kulam means pond.
Both the terms represent water only. As like Annan Kovil, this place has got its another name "Thiru Vellakulam" from the above similarity. It can also taken that Lord Rama, Balarama and Aadhi vishnu are all of white colour. Lord Krishna is of Blue colour the colour of water in ponds and tanks. Taking Vellam as Vellai White colour it can also be said that the name Vellakulam was got by the above reason.
Sri Srinivasa Perumal Temple is also called as ‘Annan Perumal Temple’, located at ‘Thiru Vellakulam’, Thirunangur, Nagapatnam district of Tamilnadu. Srinivasa Perumal Temple is dedicated to Lord Vishnu and also one of the 108 Divya Desam Temples. The mythology says that Lord Shiva had a dance of destruction (Rudra Tandava) carrying half burnt body of Goddess Sati after Goddess Sati’s self-immolation.
To stop the dance of destruction performed by Lord Shiva, Lord Vishnu threw His Chakra (Sudharshan Chakra) on Goddess Sati’s body which dismembered Her body into 52 parts.
And it is said that each time the hair of Lord Shiva touches the earth, there appeared eleven other forms of Lord Shiva. Lord Vishnu appeared in eleven forms as Lord Shiva did and solaced Lord Shiva saying that His dance of destruction may result in the destruction of entire creations on the world.The eleven forms of Lord Vishnu which appeared at Thirunangur is said to be where the eleven temples of Lord Vishnu are situated. Hence, the eleven temples at Thirunangur are very closely associated to each other in one way or the other. And it is said that Eleven Rudras (deities) and the group of Rishis were worshipped Lord Vishnu and got blessings of Lord Vishnu at Thirunangur.
The presiding deity of this Srinivasa Perumal Temple is Lord Srinivasan (Lord Vishnu) also known as Lord Annan Perumal, in a standing posture facing towards the east direction. The other main deities of this temple are Goddess Alarmel Mangai, Goddess Padmavathi, etc. Sri Srinivasa Perumal Temple is glorified in Nalayira Divya Prabandham, the great canon and the hymns were sung by Thirumangai Azhwar. The saint Thirumangai Azhwar has a separate shrine in this temple.