This section is from the book "Some Contributions Of South India To Indian Culture", by S. Krishnaswami Aiyangar. Also available from Amazon: Some Contributions of South India to Indian Culture.
The country south of the Krishna was divided among 'the three crowned Kings' and seven chieftains, with an eighth coming somewhat later. There were a host of minor chieftains of lesser dignity. It is the coast region and the more open country that belonged to the kings, while the middle regions of hills and forests belonged to the chieftains, and perhaps even a few tribes (Nagas and others). The east coast from Pulikat to the south of Tondi in the Zemindari of Ramnad, belonged to the Chola, although midway between the kingdom proper and its northern viceroyalty of Kanchi lay the hill-country round Tirukkovilur in the possession of a class of chieftains named Malayaman; and between his territory and the coast the chieftains of Oyma-nadu very often loyal supporters of their suzerain, occasionally turbulent and rebellious. South of the Chola kingdom lay that of the Pandya, which extended from coast to coast, and embraced within its borders the modern districts of Madura and Tinne-velly, and the State of Travancore, taking in also a part of Coimbatore and Cochin. This included in it the chieftaincies of Aay. (The Aioi of Ptolemy) round the Podiyil hill in the Western Ghats and the domains of Pehan round the Palnis which come under their sphere of influence as well. North of this and along the Western Ghats on the sea-side lay the territory of the Chera; a territory stretching right across the Palghat gap through Salem and Coimbatore. South Mysore was parcelled out among a number of chieftains corresponding to the modern Palayagars, whose allegiance was at the disposal of either, but the more powerful of their neighbour kings. Such were the Irungo of Araiyam, Pari of Parambunad (west of the Kaveri in Kongu), Adiyaman of Tagadur (Dharmapuri) and Ori of the Kollimalais. The first of these was within the Mysore territory proper and to the east of his domain lay the Gangas, and Kongu to the south. The northern frontier of the Tamil land was held by Nannan of the Tulu country and Konkan in the west, and Pulli of Vengadam (Tirupati) in the east, the further north having been the land of the Vadukar and Dandaranyam (Sans. Danda-karanyam).
These chieftaincies were the bone of contention between the Cholas and the Cheras. When the period under treatment begins, the Cholas were supreme under Karikala, who ascended the throne, probably after defeating the Chera and Pandya in a battle at Vennil (Koilvenni as it is now called) in the Tanjore District. He was a remarkable sovereign who, in many ways, contributed to the permanent welfare of his subjects, and has consequently been handed down to posterity as a beneficent and wise monarch. He constructed the embankments for the Kaveri, and his chief port Puhar was the great emporium of the east coast. His reign was long, and, taken along with those of his two predecessors and the successor next following him, constitutes the period of the first Chola ascendancy in the south. In the reign of his successor a great catastrophe befell Puhar, and the city and port were both destroyed. This was a hard blow to the ascendancy of the Cholas. But Karikala had,' after defeating his contemporary Chera, given probably one of his daughters (it is just possible a sister) in marriage to the son of his vanquished rival. This alliance stood the Cholas in good stead. Karikala's successor began his reign with a victory, which his heir-apparent won for him, against the Chera and Pandya combined at Kariyar, probably in the Salem District. When Puhar was destroyed, at least in part, there was a civil war owing perhaps to the untimely death of the young Chola prince; and the Chera ruler for the time being, advanced through the central region. He intervened in favour of his cousins with effect, as against the rival claimants of royal blood, and restored the Chola dynasty to some power; but the ascendancy surely enough passed from them to the Chera. 9
The Chora ascendancy under the " Red Chera " (Senguttuvan) lasted only one generation. In the reign of his successor the Pandyas rose to greater importance, and the Chera suffered defeat and imprisonment at his hands. This Pandya ascendancy probably lasted on somewhat longer till about the rise of the Pallavas in Kanchi. This course of the political centre of gravity in southern India is borne out in very important particulars by the Ceylon chronicle called the Mahavamsa. According to this work, the Cholas were naturally the greatest enemies of the Singalese rulers. There were usurpers from the Chola country in Ceylon in the first century B.C.; and there were invasions and counter-invasions as well. On one occasion the Chola invaders carried away 12,000 inhabitants of Ceylon and set them to work at 'the Kaveri' as the Chronicle has it.1 This looks very much like an exploit of Karikala seeing that it was he who either built the city of Puhar, or greatly extended it. King Gajabahu of Ceylon2 was present at the invitation of the Red-Chera, to witness the celebration............ of a sacrifice and the consecration of the temple to the "Chaste Lady " (Pattini Devi) at Vanji on the west coast.
1 Upham's Mahavamsa. Vol. i. p. 228. 2 Silappadhikaram, Canto. 30. 1. 160. apart from the prologue.
The ascendancy of the Chera, however, passed away as already mentioned, to the Pandyas in the course of one single generation. The E-ed-Chera was succeeded by his son or successor, "the Chera of the elephant look," who was his predecessor's viceroy at Tondi, and figured prominently in his wars in the middle region. He was defeated and taken prisoner in a battle, which he had to fight with the contemporary Pandyan, designated the victor at Talaiyalanganam. With this mishap to the ruler the Chera ascendancy passes away. The Pandyans of Madura take their turn now, and continued to hold the position of hegemony up to the time that the Pallavas rise into importance. This, in brief and in very general terms, was the political history of South India at the beginning and during the early centuries of the Christian era.