The term 'south India' denotes that portion of peninsular India beneath the Krishna River and the watershed of its major tributary, the Tungabhadra. The major early source of civilizational elements within the macroregion defined was the Tamil plain. The northernmost of the Tamil plain was Tondaimandalam, south of this was the territory called 'Naduvil-nadu', and, below this, in the Kaveri basin, Cholamandalam. The southern portion of the peninsula shares with the northern, Deccan, portion a peninsular configuration which emphasizes the sea and contact beyond the sub-continent by means of it. From an early time until perhaps the fourteenth century, the sea offered the south Indians opportunities for both trade and piracy. The Coromandel plain was the major core region of south India, extending from the tip of the peninsula to the northern edge of the broad delta of the Godavari and Krishna rivers. Irrigated rice culture permitted a high degree of routinization of cultivation p.