In the ancient days, Thiruvalla was a small village called Mallikavanam. The people of that village on the banks of Manimalayaar were pious and God-fearing. The place was under the rule of Thukalan, a fierce man. Thukalan was a devotee of Lord Siva and he persecuted the devotees of Vishnu. It is said that Thukalasserry near the temple got its name from Thukalan’s palace. Many Brahmins left the place unable to bear the cruelty of Thukalan but those of the Shankaramangalath family continued to live there.  Narayanan Bhattathiripad and his wife Sreedevi Antharjanam were childless and spent their time praying. They both took abstinence on Ekadashi day to more be blessed with a child. But all that was to no avail. Soon Narayanan Bhattathiripad died leaving his wife whom the villagers called Chamkrothamma all alone in this world. She continued to follow the rituals for Ekadashi. As she was illiterate, she depended on others to know the Ekadashi. Once no Brahmachary came to take food at her illam on the day of Dwadashi. As she sat in sorrow at being unable to conclude her austerities by feeding Brahmacharis, a young man arrived there. Happily, she asked him to have a bath in the pond before she could serve him food. But the boy wanted to have a bath in the river. The lady understood that it was Maha Vishnu who had come as the Brahmachari. The Lord killed Thukalan and his followers and washed his Sudarshan Chakra which he had used to kill them, at the river. The place in the river where the Lord washed his Chakra came to be known as Chakrashalanakadavu.  The idol of Lord Siva, which Thukalan had been worshipping was shifted to a temple on top of the hill. This is the Thukalassery Mahadeva Temple. The idol here is different from the Sivalingas usually consecrated in temples. There is a depression on top which is big enough to hold 36 paras of flowers. (One para weighs around 8kgs.) It is believed that when Lord Mahavishnu consecrated the idol at this temple, the idol did not become fixed in place. So, the Lord pushed it down causing the depression. The belief of the devotes is that whoever worships at the Sree Vallabha temple, should worship at the Thukalassery temple also.