Conjeevaram Natarajan Annadurai (15 September 1909 – 3 February 1969), popularly called Anna (Elder brother) or Arignar Anna (Anna, the scholar), was an Indian politician who served as 1st Chief Minister of Tamil Nadu for 20 days in 1969 and fifth, and last Chief Minister of Madras from 1967 until 1969 when the name of the state of Madras was changed to Tamil Nadu. He was the first member of a Dravidian party to hold either post.
He was well known for his oratorical skills and was an acclaimed writer in the Tamil language. He scripted and acted in several plays. Some of his plays were later made into movies. He was the first politician from the Dravidian parties to use Tamil cinema extensively for political propaganda. Born in a middle-class family, he first worked as a school teacher, then moved into the political scene of the Madras Presidency as a journalist. He edited several political journals and enrolled as a member of the Dravidar Kazhagam. As an ardent follower of Periyar E. V. Ramasamy, he rose in stature as a prominent member of the party.
With differences looming with Periyar, on issues of separate independent state of Dravida Nadu and on inclusion in the Indian Union, he crossed swords with his political mentor. The friction between the two finally erupted when Periyar married Maniammai, who was much younger than him. Angered by this action of Periyar, Annadurai with his supporters parted from Dravidar Kazhagam and launched his own party, Dravida Munnetra Kazhagam (DMK). The DMK initially followed ideologies the same as the mother party, Dravidar Kazhagam. But with the evolution of national politics and the constitution of India after the Sino-Indian war in 1962, Annadurai dropped the claim for an independent Dravida Nadu. Various protests against the ruling Congress government took him to prison on several occasions; the last of which was during the Madras anti-Hindi agitation of 1965. The agitation itself helped Annadurai to gain popular support for his party. His party won a landslide victory in the 1967 state elections. His cabinet was the youngest at that time in India. He legalised Self-Respect marriages, enforced a two language policy (in preference to the three language formula in other southern states), implemented subsidies for rice, and renamed Madras State to Tamil Nadu.
However, he died of cancer just two years into office. His funeral had the highest attendance of any to that date. Several institutions and organisations are named after him. A splinter party launched by M. G. Ramachandran in 1972 was named after him as All India Anna Dravida Munnetra Kazhagam.