Vazhappally Sasanam is the oldest rock inscription found in the state indicating Chera (Kulasekhara-Mahodayapuram) as their capital. This inscription was written in AD 830 and provides valuable insights into the Kulasekhara Dynasty. While other inscriptions begin with “Swathisree” , the Vazhapally inscriptions begin with “Namasivaya”. During this period, Sanskrit words were written in the Grandha alphabet, but the inscription discovered in the state dates back to the 8th century.

Tharisapalli plates are copper plate documents. It is also known as kollam tharisapalli copper plate. This document is the oldest available Chera Perumal inscription. It throws light on the system of taxation that prevailed in early ‘Venad’, as several taxes include professional tax, sales tax, etc.

The Sanskrit works of Kerala help reconstruct ancient and medieval history. The early sanskrit works like the Aitareya Aranyaka refer to cherapada. Ramayana mentions Kerala and also the Muchiripatanam Mahabharata mentions a Kerala king who supplied provisions in the Kurukshetra battle. The dramas of Kulasekhara demonstrate Kerala as a separate political unit during that period. The grammatical work leelathilakam refers to the rulers of Venad. The Sukasandhesa and Kokilasandhesa mention prominent pilgrim centres in Kerala.

The Tamil literary works of the sangam age provide valuable information about the life of the people in the early centuries of the Christian era. They reflect the picture of a settled society. For historians of Kerala, the most significant documents are the Pathittupattu, Akananuru, Purananuru, and Nattinai, in addition to the two epics Chilappadikaram and Manimekhalai.