Most of the people never failed to worship Lord Chandikeswarar at the time of visit to Lord Shiva temple. But, not everyone know about the transformation of Vichara Sarman (ardent devotee of Lord Shiva) into Lord Chandikeswarar.
Vichara Sarman was born in Senganoor village, Kumbakonam. This miracle happened in this place. At the age of 5, he learned all the Vedas by himself. One day, he was noticed a cowherd beating a cow & he could not tolerate this. Vichara Sarman was spoke to the cowherd: Don't you know that the cow is sacred & worshipful? All the Gods & Devas reside in her. Our duty is to protect the cows, not to harm the cows. Those who harms the cow is throwed into the hell, if you worship the cow you will wins a place in Kailasham- Shiva's abode. You committed a great sin today. Hereafter, i will do tend to the cows. He took the work upon himself from that day.
The cows grew healthier due to care showered by him on them. After supplying milk to the villagers, Vichara Sarman decided to perform Milk abishek to Lord Shiva. He build a Shiva Linga from the River Manniyar mud & regularly offer milk abishek & flowers archana to the Linga.
One day, a villager watched all the proceedings & complained to his father that he was wasting the milk on mud. Next day, his father Ecchadattan followed him at a distance without his knowledge. When Vichara Sarman began pouring milk on Lingam, his father hit him with a stick & knocked down the milk pot. At once, he took a stick & hit his father's leg. The stick was transformed into an axe by the will of Lord Shiva. It killed the father. He don't mind what had happened & continued the worship. It was to check the depth of his devotion towards Lord Shiva. No sins attached to him for killed his father, because of his great devotion to Lord. His father also attain the abode of Shiva, because he was killed by such a supreme devotee of Lord shiva.
Lord Shiva appeared before him with Parvati. Lord Shiva said: You cut your father's leg for My sake. From now, i'm your Father, you will be called as 'Chandikeswarar'. You worshipped me with milk & flower, in the same manner you will also be worshipped. Hence, Lord Chandikeswarar is worshipped in a seperate shrine in all Shiva temples.
According to Puranas, a small piece of Meru mountain (the mount that was used for churning the milky ocean) fell at this place. Hence the place was named Satyagira and the main deity of Senganoor Shiva Temple is called as Lord Satyagireeswarar.