Indo-Aryan migration
The area west of the Western Ghats became increasingly politically distinct from the Eastern parts ruled by Chola and Pandya Dynasties Kerala was until 9th century, culturally and linguistically part of Tamilakam, with the local Koduntamil evolving to Malayalam. This socio-culturally transformation was altered through Sanskrit-speaking Indo-Aryan migration from Northern India in the 8th century.