The caste system in Kerala differed from that found in the rest of India. While the Indian caste system generally divided the four-fold Varna division of the society into Brahmins, Kshatriyas, Vaishyas and Shudras, in Kerala, there existed only two varnas: Brahmins and Shudras, out of these four, while others were classified as Avarna. The Malayali Brahmins formed the priestly class .[1][2][3]Brahmins labeled all other castes as "Sat-sudra", "Shudra" and "Avarna" based on their origin and ritual rank.[4][5][6] The exception to this were Kings in Kerala like of Travancore and Cochin, who were ritually promoted to the status of Kshatriya by means of the Hiranyagarbha ceremony.[4][5][6][7][8][9]
Like the rest of India, the lower castes touching the upper castes was termed as "pollution," but only in Kerala did the lower castes pollute not just by touch but also by merely approaching an upper caste.[10][2][11][12][13][14][1]
^ abLannoy, Mark de; DeLannoy, Mark (1997). The Kulasekhara Perumals of Travancore: history and state formation in Travancore from 1671 to 1758. CNWS publications. Leiden: Research School CNWS. ISBN978-90-73782-92-1.