The Communist Party of India (CPI) is a prominent political party of the country. There are distinguished views about the formation of the party. The foundation day as they celebrate is 26 December, 1925. It is said that the CPI was founded in Tashkent on October 17, 1920, soon after the Second Congress of the Communist International. M.N. Roy, Evelina Trench Roy (Roy`s wife), Abani Mukherji, Rosa Fitingof (Abani`s wife), Mohammad Ali (Ahmed Hasan), Mohammad Shafiq Siddiqui and M.P.B.T. Acharya were the founding members of the party. Afterwards they aimed at starting a party organisation within India. `Anushilan` and `Jugantar` were the newspaper groups active in the Bengal region during that time. It was M.N. Roy who contacted these groups and attempted to form a small communist group in Bengal (led by Muzaffar Ahmed), Bombay (led by S.A. Dange), Madras (led by Singaravelu Chettiar), United Provinces (led by Shaukat Usmani) and Punjab (led by Ghulam Hussain). Eventually, only Usmani, became a CPI party member.

At the time of its formation, there was poor organisational structure within the party. In addition to that many communist groups within the party worked with restricted national coordination. At that time, all communist activities were banned by the British colonial authorities. The concept of forming a united party came out from there. In the years from 1921 to 1924, four conspiracy trials took place opposed to the communist movement. They were- First Peshawar Conspiracy Case, Second Peshawar Conspiracy Case, Moscow Conspiracy Case and the Cawnpore Bolshevik Conspiracy Case. The Cawnpore Bolshevik Conspiracy Case had an intense political impact indeed. M.N. Roy, S.A. Dange, Muzaffar Ahmed, Nalini Gupta, Shaukat Usmani, Singaravelu Chettiar, Ghulam Hussain and R.C. Sharma were accused on 17th March, 1924 in Cawnpore (now spelt Kanpur) Bolshevik Conspiracy case. The allegation was that, they, as communists were attempting "to deprive the King Emperor of his sovereignty of British India, by complete separation of India from imperialistic Britain by a violent revolution."

The Cawnpore Bolshevik Conspiracy case from then onward, was held responsible for `actively introducing communism to a larger Indian audience`. Muzaffar Ahmed, Nalini Gupta, Shaukat Usmani and Dange were condemned to several years of imprisonment. M.N. Roy and R.C. Sharma were out of British territory at that time and Ghulam Hussain was granted pardon because he confessed his association with the Russians. After the release of Dange, on 25th December 1925, a communist conference was organized in Kanpur where approximately 500 people participated. Satyabhakta convoked the conference. The name `Communist Party of India` was adopted at the conference. Groups such as LKPH (Labour Kisan Party of Hindustan) dissolved into the unified CPI. Thus Communist Party of India started its operation inside India.

Soon after the conference of the Workers and Peasants Party of Bengal in 1926, the underground CPI called all its members to link up the provincial Workers and Peasants Parties. In 1928, the 6th Congress of the Communist International took place. The turning of the Kuomintang (Chinese communist) led to a brush up in the policy of shaping alliances with the national bourgeoisie in the colonial countries. The Indian communists was called upon to fight against the `national-reformist leaders` and to `unmask the national reformism of the Indian National Congress and oppose all phrases of the Swarajists, Gandhists, etc. about passive resistance` according to the Colonial theses of the 6th Comintern congress. In the mean time the Congress party made a distinction between the character of the Chinese Kuomintang and the Indian Swarajist Party. The Workers and Peasants Party was also stigmatized by the Congress. The Indian Communists were also directed by the Tenth Plenum of the Executive Committee of the Communist International to break with WPP.

On 20th March1929 arrests were made in several parts of India against WPP, CPI and other labour leaders. This came to be known as the Meerut Conspiracy Case. The party started reorganising after the communist leaders were released in the year 1933 from the Meerut trials. In the very next year, the party was recognised as the Indian section of the Communist International. During the year 1934 the main centres of activity of CPI were Bombay, Calcutta and Punjab. CPI also started spreading their operation in Madras (currently known as Chennai). When Indian leftist elements constituted the Congress Socialist Party in 1934, the CPI stigmatised it as Social Fascist. The Congress Socialist Party used to work as the left wing of Congress. As a result of their changed relationship with the Indian National Congress, the CPI joined the Congress Socialist Party.

The first Kerala unit of Communist Party of India was founded in 1937 at a clandestine meeting in Calicut. Eminent personalities like E.M.S. Namboodiripad, Krishna Pillai, N.C. Sekhar, K. Damodaran and S.V. Ghate were present in the meeting. The first four were the members of the CSP in Kerala. S.V. Ghate was the member of CPI Central Committee. The interactions between these two parties took place through the national meetings of the Congress, CSP and All India Kisan Sabha. During 1936-1937 the cooperation reached its peak between socialists and communists. A thesis was adopted at the 2nd Congress of the CSP, held in Meerut in January 1936, which stated that there was a necessity to build `a united Indian Socialist Party based on Marxism-Leninism`. Various communists at 3rd CSP Congress were included into the CSP National Executive Committee. The Congress was held at Faizpur.

On the occasion of the 1940 Ramgarh Congress Conference the Communist Party of India brought out a declaration called Proletarian Path. The declaration was attempted to utilise `the weakened state of the British Empire in the time of war and gave a call for general strike, no-tax, no-rent policies and mobilising for an armed revolution uprising`. At the conference, it was decided by the National Executive of the CSP to expel all communists from CSP. The Communist Party of India was legalised in July 1942. However they managed to held back their control over the All India Trade Union Congress. In 1946, the communist Party of India for the very first time challenged the Provincial Legislative Assembly elections on its own. They won 8 seats out of 1585 seats. They had contested for three seats from Bengal and won all of them. CPI candidate Somanth Lahiri was nominated to the Constituent Assembly. In 1946, the Tebhaga Movement in Bengal was launched by the party. It was a militant campaign against feudalism.

After the Indian Independence, political senario was very much disorganised. The Communist Party of India wobbled rapidly between left-wing and right-wing positions. In 1948, the 4th Party Congress was held at Palghat, where the `Programme of Democratic Revolution` was adopted. In the programme `struggle against caste injustice` was discussed for the first time. The CPI led armed struggles against a series of local monarchs. In Tripura, Telangana and Kerala these kinds of insurgencies took place. The most significant insurrection took place in Telangana against the Nizam of Hyderabad. At the 1951 congress of the party, their principal slogan changed from `People`s Democracy` to `National Democracy`. The Communist Party of India raised as the largest opposition party in the general elections held in the year 1957. In the same year, they won the state elections in Kerala and this led the party to win control over an Indian state for the first time. It was indeed an honour for an opposition party. E. M. S. Namboodiripad became the Chief Minister. They received criticism at the 1957 international meeting of communist parties held in Moscow.

But the Communist Party of India experienced their rift within the party during the year 1962. Sino-Indian War was looked at as the reason behind this. Because of the war, a section of the Indian communists plunked for the position of the Indian government and others affirmed it as a conflict between a socialist and a capitalist state, and thus took a pro-Chinese position. The CPI divided into three section of internationalists, centrists, and nationalists. Prominent leaders like S.A. Dange, A. K. Gopalan, and E. M. S. Namboodiripad were in the nationalist faction; B. T. Ranadive, Sundarayya, P. C. Joshi, Basavapunniah, Jyoti Basu, and Harkishan Singh Surjeet were amongst those backed up China; Ajoy Ghosh in the centrist faction. Communist leaders from Bengal supported China and rest India.

These kind of ideological divergences contributed to the split in the party in 1964. The Communist Party of India and the Communist Party of India (Marxist) breached out. It would be wrong to identify the Sino- Indo war as the only reason behind this split up. The split was between leftists vs rightists and not internationalists vs nationalists. The presence of nationalists in the Communist Party of India (Marxist) like A. K. Gopalan, and E.M.S. Namboothirippad, and internationalists P. Sundarayya, Jyoti Basu, and Harkishan Singh Surjeet proved the fact. During 1970-77, the Communist Party of India was united with the Congress party. With CPI-leader Achutha Menon as Chief Minister they formed a government together with the Congress in Kerala. Later, the CPI again oriented itself with Communist Party of India (Marxist).

Today, the Communist Party of India is recognised as a `National Party` by the Election Commission of India. CPI happens to be the only national political party from India to have contended all the general elections using the same electoral symbolic representation. Presently they are supporting the Indian National Congress-led United Progressive Alliance government without taking part in it. The Communist Party of India in West Bengal is an alignment of several Leftist and other communist parties, known nationwide as the Left Front-government. They are also a part of Manipur Government. It is part of Left Democratic Front in Kerala. It is part of the Progressive Democratic Alliance in Tamil Nadu. CPI has some principal mass organisations like, All India Trade Union Congress; All India Youth Federation; All India Students Federation; National Federation of Indian Women; All India Kisan Sabha (peasants organisation); Bharatiya Khet Mazdoor Union (agricultural workers); All India State Government Employees Federation (State government employees). Ardhendu Bhushan Bardhan is the current general secretary of CPI.