There are literary, archaeological, epigraphic and numismatic sources of ancient Tamil history. The foremost among these sources is the Sangam literature, generally dated to the last centuries BCE to early centuries CE. The poems in Sangam literature contain vivid descriptions of the different aspects of life and society in Tamilakam during this age; scholars agree that, for the most part, these are reliable accounts. Greek and Roman literature, around the dawn of the Christian era, give details of the maritime trade between Tamilakam and the Roman empire, including the names and locations of many ports on both coasts of the Tamil country.
Archaeological excavations of several sites in Tamil Nadu have yielded remnants from the Sangam era, such as different kinds of pottery, pottery with inscriptions, imported ceramic ware, industrial objects, brick structures and spinning whorls. Techniques such as stratigraphy and paleography have helped establish the date of these items to the Sangam era. The excavated artifacts have provided evidence for existence of different economic activities mentioned in Sangam literature such as agriculture, weaving, smithy, gem cutting, building construction, pearl fishing and painting.
Inscriptions found on caves and pottery are another source for studying the history of Tamilakam. Writings in Tamil-Brahmi script have been found in many locations in Kerala and Tamil Nadu, mostly recording grants made by the kings and chieftains. References are also made to other aspects of the Sangam society. Coins issued by the Tamil kings of this age have been recovered from river beds and urban centers of their kingdoms. Most of the coins carry the emblem of the corresponding dynasty on their reverse, such as the bow and arrow of the Cheras; some of them contain portraits and written legends helping numismatists assign them to a certain period.
