the Party (nomenklatura). The city of Poznań was one of the largest urban and industrial centers of the Polish People's Republic. Tensions were growing there, particularly since autumn of 1955. Workers in the largest factory in the city, the Joseph Stalin Metal Industries, were complaining about higher taxes for the most productive workers (udarnik), which affected several thousands of workers. Local directors were unable to make any significant decisions due to micromanagement by the higher officials; over several months, petitions, letters and delegations were sent to the Polish Ministry of Machine Industry and the Central Committee of Polish United Workers' Party, to no avail. Finally, a delegation of about 27 workers was sent to Warsaw around 23 June. On the night of 26 June, the delegation returned to Poznań, confident that some of their demands had been considered in a favourable light. However, the next morning, the Minister of Machine Industry met with the workers and withdrew several promises that their delegation had been given in Warsaw. Strikes On 28 June 1956, a spontaneous strike started at 6 a.m. at the multifactory complex of the Joseph Stalin Metal Industries. Around 80% of its workers, most of whom had lost bonus pay in June as the government suddenly raised the required work quota, took to the streets demanding pay compensation and some concessions of freedom, marching towards the city centre. Workers at other plants, as well as institutions and students, joined the procession. Between 9 and 11 a.m., about 100,000 people gathered on the Adam Mickiewicz Square in front of the Imperial Castle in Poznań, surrounded by buildings occupied by the city and Party authorities and police headquarters. The demonstrators demanded lower food prices, wage increases and the revocation of some recent changes in the law that had eroded workers' conditions. They further requested a visit from Polish Prime Minister Józef Cyrankiewicz, as the local government declared that they had no authority to solve the workers' problems. Some police officers also joined the crowd. After 10 a.m., the situation rapidly deteriorated, with rumours spreading that members of the negotiating delegation had been arrested. The local units of the regular police (Milicja Obywatelska) were unable to contain the crowd and the situation turned into a violent uprising as the crowds stormed the prison at Młyńska Street, where members of the delegation were believed to have been imprisoned; hundreds of prisoners were released