C. Iyothee Thass (20 May 1845 – 1914) was a prominent Tamil anti-caste activist and a practitioner of Siddha medicine. 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 Panchamar Mahajana Sabha in 1891 along with Rettamalai Srinivasan. Panchamas are the ones who do not come under Varna system; they are called as Avarna communities.
“Iyothee Thass” is the most common Anglicized spelling of his name; other spellings include Pandit C. Ayodhya Dasa, C. Iyothee Doss, C. Iyodhi Doss, C. Iyothee Thoss, K. Ayōttitācar (avarkaḷ), K. Ayōttitāsa (paṇṭitaravarkaḷ), or Ayothidas Pandithar.
For more visit: [https://en.wikipedia.org/wiki/Iyothee_Thass]