Hello,

Tamilaham, or Thamizhagam, refers to the geographical region that is inhabited by the ancient Tamil people. Tamilaham covers today's Tamil Nadu, Kerala, Puducherry, Lakshadweep and some southern parts of Andhra Pradesh and Karnataka. The traditional accounts and Tholkppiyam referred these territories as a single cultural area, where Tamil was the natural language and culture of all people.The ancient Tamil country was divided into many kingdoms. The best known among them were  Cheras, Cholas, Pandyans and Pallavas.

During the Sangam period, Tamil culture began to spread mostly outside Tamilaham. Ancient Tamil settlements were also found in Sri Lanka and the Maldives.

Hope this helps you.