There are large gaps in the known early history of the Kerala region, which in the 1st-century AD is thought to have been governed by the Chera dynasty and which by the late 3rd-century AD had broken up, possibly as a consequence of a decline in trade with the Romans. There is no evidence of Nairs in the area during this period. Inscriptions on copper-plate regarding grants of land and rights to settlements of Jewish and Christian traders, dated approximately between the 7th- and 9th-centuries AD, refer to Nair chiefs and soldiers from the Ernad, Valluvanad, Venad (later known as Travancore) and Palghat areas. As these inscriptions show the Nairs as witnesses to the agreements between those traders and the successors to the Cheras, the Perumals, it is probable that by this time the Nairs were vassal chieftains.