The Sage who is said to have Aryanised South India, was

The age of vedic Risi Agastya, who is said to have established brahmanical settlements on the distant Podiyur hill(Tennevelly district), besides those in the Dekkan. The traditional division of Southern India was into three kingdoms- Ceras of Malabar, Pandyas of Madurai and Tinnevelly and the Colas who ruled tract above the Pandyas upto the Penner river. Agastya was the first to write grammar of Tamil language. He spread the Aryan culture and literature in South India.