I couldn’t think of a better way of introducing lord of Thiruvallur.
The moolavar in Thiruvallur is seen reclining on Ananda (five headed snake popularly known as Adhishesa) in Bhujanga sayana (Bhujanga means serpent). The lord’s right hand is positioned on Salihothra rishi’s head while the left hand is in the Gyana Mudra position indicating the teaching of the four Vedas to the Lord Brahma who is seen emerging from the umbilicus (Naabhi Kamalam) of the Lord.
As per learned Vasishnava scholars, initially the lord was called ‘Evvul Kindanthan’ up to to the time of Thirumangai Alwar. Thirumangai Alwar while singing the praise of the lord visualized and referred to the lord as Sri Veera Raghavan. Pasurams 2.2.1 and 2.2.2 of Periya Thirumozhi, sung by Thirumangai Alwar, describes the lord as Lord Rama. From then on the lord has been referred as Lord Veera Raghavan. Logic is if the lord was Rama then he wouldn’t have Sridev and Bhudevi by his side. As the lord residing here is able to cure all the illnesses he is popularly called Vaithiya Veeraraghavan.
Taayaar of this divya desam is Kanakavalli thaayaar and is in a separate sannidhi. Taayaar is also called Vasumathi, the legend goes that lord married the Thaayar, who borne in this sthalam as the daughter of King Dharmasenan and was named "Vasumathi".
Mangalaasaasanam: Tirumangai Alwar has sung 11 pasurams (1058-67, 2674 (116)) and Tirumazhisai Alwar has sung 1 pasurum (2417) praising the lord. The pasuram numbers refered are as found in Naalaayira Divya prabhandam. Interestingly even Ramalinga Adigalaar has sung in praise of the deity at Tiruvallur.
Location: Tiruvallur is on the Chennai Tirupati highway. It is about 40 Kms from Chennai. Need to go into the town of Thiruvallur while passing the town on the highway.