Formed in 1941, with Soleiman Mirza Eskandari as its head, it had considerable influence in its early years and played an important role during Mohammad Mosaddegh's campaign to nationalize the Anglo-Persian Oil Company and his term as prime minister.

[7] From the Iran crisis of 1946 onwards, Tudeh became a pro-Soviet organization and remained prepared to carry out the dictates of the Kremlin, even if it meant sacrificing Iranian political independence and sovereignty.

Being close to the Soviet Union and the Caucasus, northern Iran became the primary center of underground Marxist and social democrat political activity, and many such groups came into being over the years.

Many political prisoners subsequently received general amnesty by his son and successor Mohammad Reza Pahlavi,[18] and under this new atmosphere, nationalist and socialist groups once again flourished.

"At Soleiman Eskandari's urging", the party initially attempted to appeal to non-secular masses by barring women from membership, organizing Moharram processions, and designating "a special prayer room in its main clubhouse."

British ambassador Reader Bullard called it the only coherent political force in the country, and the New York Times reckoned it and its allies could win as much as 40% of the vote in a fair election.

[25] This period has been called the height of the party's intellectual influence which came in large part from the prestige and propaganda of the Soviet Union as "the world's most progressive nation."

"[27] From the Iran crisis of 1946 onwards, Tudeh became a pro-Soviet organization and remained prepared to carry out the dictates of the Kremlin, even if it meant sacrificing Iranian political independence and sovereignty.

[8][9] Based on increasingly available archival material from Russia, Iranologist Soli Shahvar contends that this was true much earlier—dating back to the Tudeh Party's inception, not just during the Fourteenth Majlis election campaign.

"[33] The party continued to function underground however and by 1950 it had organized its supporters under the banner of the Iran Society for Peace (Jam'iyat-e Irani-ye Havadar-e Solh) and was publishing three daily papers, Razm, Mardom, and Besui-ye Ayandeh.

[34] One Iranian conservative newspaper even editorialized: "...the Tudeh Party, with its satanic doctrine of class struggles, has incited ignorant workers to violate the sacred right of private property and inflict social anarchy upon the center of the country.

"The party played an important role both directly and indirectly during the pivotal era of Iranian history that began with the 1951 nationalization of the British Anglo-Iranian Oil Company (AIOC), and ended with the 1953 overthrow of Mohammad Mosaddegh by a CIA-led coup d'état.

[37] In early April 1951, the Tudeh revealed its "true strength" by launching strikes and riots protesting low wages and poor housing and delays in the nationalization of the oil industry.

In a June 1950 article in its daily Mardom it described the effects of Mosaddegh's policy thusly: Already we can be sure that revisions in the southern oil contract will not be in favor of our people and will only result in the consolidation of England's position in our country.

[43]Ayatollah Abol-Ghasem Kashani, who later switched sides and supported the Shah, "sent a public letter to the pro-Tudeh organizations thanking them for their invaluable contribution" during the uprising toward Mosaddegh's victory.

[45] With the Soviets not wanting to back or "shore up" Tudeh, and Truman refusing demands to overthrow Mosadegh from Clement Attlee and Winston Churchill, it would take the inauguration of Dwight Eisenhower to change the tune, greenlighting the coup operation.

[49] In 1953, American CIA and British intelligence agents, began plotting to overthrow Mosaddeq in a coup d'état, in large part because of their fear that "rising internal tensions and continued deterioration ... might lead to a breakdown of government authority and open the way for at least a gradual assumption of control by Tudeh," just as a local communist party had led a coup in Czechoslovakia in 1948, replacing a democratic regime and constitution with a pro-Soviet, one-party Communist government.

The coup was a major event in Third World and 20th Century history and there is debate as to how much of the blame for the overthrow can be traced to bribes paid by the CIA and how much to domestic dissatisfaction with Mossadegh.

[58][59][60] Whatever the motivations, Mohammad Reza Pahlavi thereafter assumed dictatorial powers and banned most political groups, including Mosaddegh's National Front, which along with the Tudeh Party, continued to function underground.

[67] In 1965, the party faced a second division between the mainstream of the organization and the splinter faction, which advocated a violent struggle against the government by arming the tribes of southern Iran.

In 1966, several party members, including Ali Khavari and Parviz Hekmatjoo of the Central Committee, and Asef Razmdideh and Saber Mohammadzadeh, were arrested and sentenced to death.

[68] The Tudeh Party drastically increased its activities, recruiting many youths and organizing regional committees, supporting the Islamic Revolution when others on the left opposed it.

[citation needed] During the revolution, many political prisoners were freed and the Tudeh Party and other leftist groups were able to participate in the presidential and parliamentary elections for the first time in many years.

The newly elected president, Abolhassan Banisadr, who had originally been close with Ayatollah Khomeini, also became increasingly frustrated with the developments that had been taking place and opposed the domination of the clergy and the religious factions in Iranian politics.

Armed revolutionary committees loyal to Khomeini (which came to be known as the Pasdaran) arrested many thousands of youth and activists from both nationalist and leftist groups, many of whom were later tried by Lajevardi, known as the Hanging Judge, and executed.

British officials were pleased by the repression not primarily because they were concerned about Soviet influence in the country since they knew that Iran was quite independent of that, but because they wanted to curry favor with the Iranian regime.

He now realized that his entire life's work was 'defective', 'damaging', and 'totally spurious' because it had all been based on unreliable thinkers – Freemasons nourished by the Pahlavis; secularists such as Ahmad Kasravi; Western liberals and Marxists linked to 'imperialism' and 'Zionism' …[77] In his recantation, Tabari made frequent references to religion, the Twelve Imams and Islamic thinkers and "praised Islam for its `great spiritual strength.`"[78] The suspicions of outside observers that the confession was not given freely were reinforced by the absence of Taqi Keymanash and "13 other members" of the Tudeh central committee, who died during prison interrogation.

The simplest explanation came several years after the television recantations, from a prison visit by a United Nations' human rights representative (Galindo Pohl) to Iran.

Pohl added that Maryam Firuz had difficulty hearing, swallowing food, and sitting down because of beatings suffered eight years earlier at the hands of the Shah's secret police.

Though since the Iranian Revolution the party is officially banned in Iran and individuals found to be affiliated with communist or socialist groups risk imprisonment, active members have remained and it continues to operate as an underground political organization there.