Tamil Sangam-works like Manimekhalai indicate that there were Buddhists in Tamil Nadu and that the Buddhist missionaries were active in spreading their religion. According to the Sangam tradition, there was a famous Buddhist chatty a (temple) at Vanchi (Karur) and a Palli Bana Perumal became a Buddhist.
The Cheras were originally Mundas, many of whom were Buddhists even before their arrival in Tamil Nadu. It was they as well as the Buddhist missionaries from the Maurya Empire that brought the religion of Buddha to the South. They were distinctly a powerful minority in Tamil Nadu and were subjected to per-secution by the Brahmin Counsellors of the Dravidian Hindu Kings during the ascendancy of Brahminical Hinduism in the South. Aalavaipathikam records that around 640 A.D., Sambanda Murti, a Brahmin, won over the Pandya royal family and caused the massacre of 8,000 Buddhist monks in Madurai; Buddhist nuns were reportedly made into devadasis and relocated in the Hindu temple precincts. The persecution and eventual exodus of Buddhists from Tamil Nadu to Kerala in the seventh century was occasioned by the fall of the Buddhist Kalabhras at the hands of the Pandyas.
The Buddhists came to Kerala and established their temples and monasteries in different parts of the country. The following Hindu temples were once Buddhist shrines: the Vadakkunnathan Temple of Trichur, the Kurumba Bhagavathi Temple of Cranganore, and the Durga Temple at Paruvasseri near Trichur. A large number of Buddha-images have been discovered in the coastal districts of Alleppey and Quilon; the most important Buddha-image is the famous Karumati Kuttan near Ambalappuzha. Buddhism probably flourished for 200 years (650-850) in Kerala. The Paliyam Copper Plate of the Ay King, Varaguna (885-925 A.D.) shows that the Buddhists enjoyed some royal patronage even in the tenth century.
The decline of Buddhism started in the eighth century with the arrival of the Aryan missionaries and the Brahminical religion. As mentioned earlier, the Brahmin scholars defeated Buddhist monks in debates and established the superiority of the Hindu religion. Adi Sankaracharya, the Hindu revivalist, was also responsible for the fall of Buddhism; he founded Hindu monasteries and trained Hindu priest-scholars to combat his Buddhist adversaries. Buddhism faded away gradually and completely disappeared during the reign of the Vaishnavite Kulasekharas in the eleventh century. What actually happened was that Buddhism was reabsorbed into Hinduism from which it broke away. Many Keralites, like the Ezhavas, who were most likely Buddhists once, gradually became Hindus.
Buddhism has left its impact on Kerala. The images and tall rathas (cars) used in temple processions, and utsavams (fairs) are said to be Buddhist legacies. The Ayurvedic system of medical treatment is also a gift of Buddhism. Buddhists opened schools [in pallikudam and ezhuthupally. Pally is the Buddhist term for school) near their monasteries. Kerala temples show traces of Buddhist art and architecture. Amarasimha, the author of the popular Sanskrit text-book used in Kerala schools until recently, was a Buddhist. Kumaran Asan, the great Kerala poet, was influenced by the great Buddhist religion and wrote the famou, Buddhist poems: Karuna. Chandala Bhikshuki, and Sri Buddha Charitam.