The Thiruvenkadu Swetharanyeswarar temple is a very ancient temple where the presiding deity is called Swetharanyewarar and His consort is called Brahma Vidhyambigai. It is believed that the God of Creation Lord Brahma, Lord Indhra and His White Elephant had visited this temple and worshipped the Deity. There is yet another shrine for Lord Agora Moorthy who is another incarnation of Lord Shiva. Agora Moorthy is believed to destroy the demon Padmasuran. Thiruvenkadu, one of the navagraha sthalams, is the Budhan sthalam dedicated to Planet Mercury. Thiruvenkadu’s Sanskrit name is Shwetaranya and both literally mean – sacred white forest. This is also called Adhi Chidambaram and the Chidambara Rahasyam is also here. As seen in Chidambaram, Vishnu is near Nataraja. It is situated 15 kilometers away from Vaitheeswaran Koil, on the Sirkali – Poompuhar road. Here the Lord is Shwetaranyeswarar and His consort is Brahma Vidyambal. Indran, Airavatam, Budhan, Suryan and Chandran are said to have worshipped Shiva here.
Thiruvenkadu is one of the six places considered to be equivalent to Kasi. The other five are Rameswaram, Srivanchiyam, Gaya, Thiriveni Sangamam & Thilatharpanapuri. Marutwasura, an asura, was troubling the Rishis and the people of Thiruvenkadu. The people prayed to Lord Shiva. Lord Shiva sent Nandi (Bull) – his vahana, to fight the demon. Marutwasura was defeated by Nandi and thrown into the sea. Marutwasura through his penance obtained sula – from Lord Shiva. The demon then returned with greater intensity to attack the innocent people. Once again, at the request of the devotees, Shiva sent Nandi. However, on this occasion, Nandi could not fight the demon as the demon had the Sula of Shiva.
From the stone inscriptions found inside this temple, it can be seen that the earlier Chola kings Aditya Chola and Rajaraja Chola made a lot of contributions to this temple. There are several shrines of significance in this well visited temple, including those to Durga and Kali. The image of Natarajar here is of great beauty. Worship to Aghoramurthy (Veerabhadrar) is said to be of significance on Sunday nights in this temple. As found in Chidambaram, there is also a shrine for Lord Vishnu near the shrine for Natarajar.
Swetharanyeswarar is the main God in this temple. It is said that Agora Murthi was one of the furious incarnation of Shiva. There was a demon named Maruthuvasuran in Thiruvengadu. He performed penance to please Brahma for attaining special powers. Pleased by his devotion, Brahma offered him special powers. Maruthuvasuran started misusing his powers to torture the saints and innocent people. All the suffering saints and people requested Shiva to put an end to their hardship. Shiva took an incarnation as Agora murthi and killed Maruthuvasuran under a tree which is believed to be the place where Thiruvengadu temple is located. The place is called by other names like Swetaranyam, Adi Chidambaram and Nava Ntirya Stala. Indiran, Airavatan, Budha, Sooriyan and Chandiran are said to have worshipped Swetharanyeswarar here.
As per another legend, Achyutha Kalappalar, a local chieftain was childless. His guru Sivacharya analyzed his horoscope and read out an ancient palm leaf manuscript. It had the verse of Sambandar, one of the major Saivite saints Nayanars. Chieftain was advised to pray at Venkadu to be blessed with a progeny. He prayed at the place along with his wife and was blessed with a boy. The boy later went on to write Sivagnana Bodham.
As per Hindu legend, Budhan, was the child of Chandran and Dharai. Dharai was originally the wife of Guru, but had an illicit relationship with Chandran. Dharai was directed by Shiva and Brahma to back to his husband Guru and she entrusted the child to Chandra. Budha grew up to learn his background and started hating his father Chandra. He did severe penance praying Shiva. Pleased by his devotion, Shiva blessed him to be a Navagraha.Brahma was blessed with divine power of learning (Vidya) by goddess Parvathi in the temple. Pillai Idikki Amman, an idol depicted hold a child on her hip is believed to be the depiction of Parvathi holding the child Sambandar when the latter called her Amma.