Iyothee Thass
C. Iyothee Thass was a prominent Paraiyar and anticaste activist and a practitioner of Siddha medicine who is regarded as a pioneer of the Dravidian Movement. He famously converted to Buddhism and called upon the Paraiyars to do the same, arguing that this was their original religion. He also founded the Punchmar Mahajana Sabha in 1891 along with Rettaimalai Srinivasan. Punchamas are the one who does not come under Varna system. They are called as Avarnas.
Iyothee Thass was born Kathavarayan onMay 1845 in a Tamil family from Coimbatore district.9 His grandfather worked for George Harrington in Ooty and little Kathavarayan profited immensely from this association. Soon, he became an expert on Tamil literature, philosophy and indigenous medicine and could speak Tamil, English, Sanskrit and Pali.
Source: Wikipedia