Malayapuram Singaravelu Chettiar (18 February 1860 – 11 February 1946), also known as M. Singaravelu and Singaravelar, was a pioneer in more than one field in India. In 1918, he founded the first trade union in India. On May 1, 1923 he organized the first ever celebration of May Day in the country. Chettiar was a major leader of the Indian independence movement, initially under the leadership of Gandhi, but later, joining the budding communist movement. In 1925, he became one of the founding fathers of the Communist Party of India; and chaired its inaugural convention in Kanpur. Though the British Government arrested him along with other leaders on charges of conspiring to wage war against the Crown, he was set free, soon after, on account of his failing health.
Chettiar was also a path-breaking social reformer who in his early life took to Budhism, seeing it as a weapon against the evil of untouchability, which was particularly severe in the 19th-century India. He was also in the forefront of Self respect movement, in the Madras Presidency that fought for equal rights for backward castes. Though in his advanced years, he withdrew from active politics, Chettiar remained a staunch advocate of the causes he had pioneered till his death at the age of 85.
Read more about Malayapuram Singaravelu Chettiar: Early Life, Chettiar and Early Labor Movement, Chettiar and The Congress, Formation of Communist Party of India, Chettiar and Railway Employees' Strike, Chettiar and The Self-respect Movement