Thondaman Birth History and Why Lord Venkateswara Donated Sanku Chakra, a story from Brahmanda Purana.
Once, there was a Vaikhanasa Brahman, named Gopinatha, in the Chola Kingdom. He was a great devotee of Krishna. He requested the Lord to grant him salvation. Krishna asked him to go to Seshadri and worship Srinivasa there and assured him that a Sudra, named Rangadasa, would meet him on the way and be of use to him. The brahman came to the foot of the hill and there met Rangdasa. The two went up the hill and dug the image of the Lord from out of the anthill. They installed it in a mandap with a thatched roof and built a stone wall around it. Rangadasa used to fetch flowers and make garlands out of them and Gopinatha was worshipping the Lord.
One day, as Rangadasa was preparing the garlands, he saw a Gandharva couple sporting. Unable to control his mind and this sporting polluted his mind. Repenting for this, he threw away the garlands and flowers, already prepared, had a purification bath, gathered fresh flowers, made new garlands and went into the shrine. Gopinatha chided him for being late but Rangadasa did not explain the reason for the delay because of shame.
A divine voice told Rangadasa ‘ Your mind is upset. You cannot do any good deed in this condition. Be born again and this time as a king. Enjoy all worldly pleasures. Then build a good abode for me and attain Moksha .”
Rangadasa died and was born as a king. He came to be called Chakravarthi and the people of the Dravida country called him Thondaman. He lived at Narayanavanam and used to go to Seshachala every day to worship the Lord. In the course of time, he built the temple for the god with two Prakaras and two gopuras. the Garbagriha, kitchen, Yagasala, granary and Gosala. He presented many jewels to the god and instituted many festivals.
Once a number of enemies invaded his territory and harassed him. The king went to the Lord and sought his help. The god lent him his own Sanku and Chakra. The king defeated and drove away from the enemies and came back to the Lord. He then requested the Lord to stay as he was without the Sanku and Chakra and that his archa-image should be without them. The Lord agreed.