When the Satavahanas were building an empire in the Deccan, the Tamils in their homeland were divided into three monarchies and a number of petty principalities and ruled themselves.
The Tamils called their homeland Tamilaham which the Greeks who traded with them knew as Damirike. Tamilaham denoted a cultural area and included all the land lying to the south of Venkatam (the Tirumalai hills) in the north-east and of Mysore in the north-west and the triangular strip of land lying between the Arabian Sea and the Bay of Bengal.
As we have seen in the chapter on 'Geography' this territory has the varied characteristics of agricultural lands, pastures, the forests, the littoral and the tracts reduced to waste by the denudation of fertile lands. The Tamils perhaps thought that these geographical features were common to the whole world and so made a theoretical postulate that all territories everywhere consist of these divisions.
We have also seen how the Dravidians trekking south-eastwards from the eastern shores of the Mediterranean reached the Tamil country in the proto-historic times and as a racial layer imposed themselves on the pre-existing proto-Australoids. Some of them settled themselves on the banks of rivers, some others cleared the forest and dwelt therein and a few others settled on the coastal areas and minded their accustomed occupation of navigation.
It is difficult to say when these things happened. But ever since the dawn of history we hear of the three monarchies namely the Chera, the Chola and the Pandya. The earliest mention of one of these i.e., the Pandyas occurs in Megasthenes. His contemporary (if he was that) Kautilya also mentions the Pandyas.
The Mahabharata and the Ramayana also do so. But the first source to mention all the three together are the edicts of Asoka, who in his commands (numbers 2 and 13) mentions not only the three Tamil kingdoms but also neighbouring states like Ceylon and the land of the Satiyaputras.