The Anti-Hindi agitations began in pre-Independence era in the Indian state of Tamil Nadu (formerly Madras State and part of Madras Presidency), which stretched to post-Independence periods. The agitations hugely criticised, through mass protests, riots, student and political movements the imposition of the official status of Hindi in the state and in the Indian Republic.
English was the official language during the British Raj. To make Hindustani as a common language to unite various linguistic groups against the British Government, in 1918, Mahatma Gandhi established the Dakshin Bharat Hindi Prachar Sabha (Institution for the Propagation of Hindi in South India).
In 1925, the Indian National Congress adopted Hindustani for conducting its proceedings. It was supported by Gandhi and Jawaharlal Nehru. Also Congress wanted to propagate the learning of Hindustani in non-Hindi speaking Provinces of India. But this was opposed by Periyar, who viewed it as an attempt to make Tamils subordinate to North Indians.
1937 Election in Madras Presidency: the Beginning.
After the 1937 elections in Madras Presidency, the Indian National Congress formed the government and C. Rajgopalachari (Rajaji) became the Chief Minister. He was a supporter of propagating Hindi in South India. Even before the elections, he had expressed support for Hindi in a newspaper article (Sudesamithran, 6 May 1937):
"Government employment is limited. All cannot get it. Therefore one has to search for other jobs. For that and for business, knowledge of Hindi is necessary. Only if we learn Hindi, the south Indian can gain respect among the others."
Within a month of coming to power, he started his move of promoting Hindi by issuing a policy statements, introducing teaching in secondary schools and lobbying by pro-Hindi organisations like Hindustani Seva Dal and Hindustani Hitashi Sabha. This was opposed by Periyar and the opposition Justice Party led by A. T. Panneerselvam. With same objective, an Anti-Hindi conference was organised in October 1937 to protest the announcement.
Meanwhile, in 1938, Rajaji passed a government order (G.O) making the teaching of Hindi compulsory in 125 Secondary schools in the Presidency. This move was viewed by Hindi's opponents as an attempt to destroy Tamil and promote Hindi. Thus, it led to wide protests against Rajaji and Hindi, which involved protest marches, anti-Hindi conferences, observing an anti-Hindi day (1st July and 3rd December 1938), fasts against government policies, black flag demonstrations and picketing of government offices and institutions.
The agitation lasted till the order was withdrawn in February 1940.