Short answers, pulled from the story.
The Tudeh Party of Iran was founded on the 29th of September 1941. It was formed in the immediate aftermath of the British-Soviet Allied invasion that ended Reza Shah's reign, with Soleiman Eskandari elected as its first party president.
The Tudeh Party's military wing, the TPMO, uncovered the first coup attempt on the 15th of August 1953 and arrested the contingent sent to arrest Mosaddegh. However, two days later, Tudeh militants staged demonstrations that prompted Mosaddegh to call out the military, and the party then demobilized its forces the next day, leaving it unable to resist the successful CIA-backed coup on the 19th of August.
In February 1983, the Iranian government arrested the Tudeh leadership and disbanded the party after a KGB defector named Vladimir Kuzichkin passed intelligence to British and American services, which then shared it with Iran. More than 10,000 party members were imprisoned, and around 90 Tudeh prisoners were reported killed in just some blocks of Evin and Gohar Dasht prisons during the 1988 executions of political prisoners.
By early 1945, police records estimated around 2,200 hard-core Tudeh members, approximately 700 of them in Tehran, with tens of thousands of sympathizers in youth and women's organizations and hundreds of thousands more in labor and craft unions. The party's newspaper Rahbar carried a circulation of more than 100,000 copies, triple that of the semi-official Ettela'at.
From the 1st of May 1983 to the 1st of May 1984, nearly all Tudeh leaders appeared in government-broadcast videos renouncing Marxism and praising the Islamic Republic. On the 1st of May 1984, senior figure Ehsan Tabari, described as having fifty years of leftist experience, declared his life's work "defective, damaging, and totally spurious." UN human rights representative Galindo Pohl later reported that General Secretary Noureddin Kianouri displayed a badly set broken arm as evidence the confessions were extracted under torture, and fourteen central committee members died during prison interrogation.
The Tudeh Party remains officially banned in Iran and operates as an underground organization domestically. Its leadership and Central Committee, elected in 1992, are based in exile. The party continues to issue statements on Iranian and international politics, most recently calling for continued resistance during the 2025-2026 Iranian protests while opposing any foreign military intervention or restoration of the monarchy.