Elamkulam Manakkal Sankaran Namboodiripad, popularly known by his initials 'E. M. S.' was an Indian communist politician and theorist, who served as the first Chief Minister of Kerala in 1957–1959 and then again in 1967–1969. As a member of the Communist Party of India (CPI), he became the first non-Congress Chief Minister in the Indian republic. In 1964, he led a faction of the CPI that broke away to form the Communist Party of India (Marxist).
