Kumbakonam Western Gateway Dated 23000 BC

But Trade was also carried out through  western ports on the Arabian sea.

Chera kings used this route.

But for the Chola’s,whose Ports were in the East,had to reach the western ports .

And they used Kumbakonam as the Entry point to the western Ports.

The early Chola,Karikal Valavan held Court in Kumbakonam.

Become Invisible In Pond Thiruvellarai Oldest Vishnu Temple

The Tamil Cholas are referred to as the descendants of Ikshvaku Clan,to which Lord Rama belonged.
So the refernce to a temple earlier to that of Srirangam gains credibility.
The Temple of Pundarikaksha(Vishnu) is mentioned in Sangam Classics and also referred to in King Rajaraja’s inscriptions.