In the mid-1950s, following Stalin's death, the communist system imposed on the Central and Eastern Europe ceased to be a monolith. The changes under way in the USSR have forced the communist authorities in Poland to review their policy. The first attempts at criticizing the "security", the much-hated pillar of the communist power in Poland led to loosening the grip of a psychosis of fear.

The immediate reason of the outburst of dissatisfaction in Poznań was the issue of irregularities in calculating wages, unrealistic indicators of production growth and efficiency, as well as very poor working conditions in the plants. The place where the feelings of dissatisfaction converged were the former Hipolit Cegielski Poznań factories, renamed after the war to J. Stalin Poznań (ZISPO) factories. The staff of Cegielski had been since 1995 notifying their dissatisfaction with the irregularities in calculating taxes and wages. Workers also complained at bad work organisation. In the face of the fact that the management was unable to meet the workers' demands, representatives of ZISPO staff tried to contact relevant ministries and party authorities. They sent petitions, letters and delegations. The last one went to Warsaw on 26th June 1956 in order to present staff demands. Other plants in Poznań observed with great interest this active approach of HCP staff. The atmosphere was very tense. There were many guests from both Poland and abroad in the city at that time because the city was hosting Poznań International Fair. On the night of 26th June a delegation of workers came back to Poznań, confident that some of their postulates had been positively considered. The next morning, the minister of Machine Industry arrived at the factory and withdrew some of the Warsaw agreements with workers during a mass meeting. In such tense situation, the morning of 28th June witnessed workers' riots in Poznań....

Poznań June has led to political changes in October 1956, and this first mass social protest against the communist regime paved the way to the full independence regained by Poland.
Owing to foreign witnesses of the Poznań Black Thursday events, the information concerning these events reached the West and showed the true colors of socialist democracy to the public opinion. At the same time, after the October transformations in Poland, a decision to draw a "curtain of silence' over the Poznań events was taken very quickly. For the next 25 years the communist authorities blocked any information on these bloody events. Historians were denied any source research, and the censorship effectively eliminated any mentions of June 1956. The most active participants of these events have been persecuted for years.
The memory of June 1956 was cherished by the families of participants of these events and among the residents of Poznań. Graves of the fallen, buried at night and under guard of Security officers, were treated with respect and remembrance. Behind the curtain of silence, the legend of the Poznań Black Thursday began to emerge based on memories and oral transmissions.
A breakthrough in the struggle for remembrance of June 1956 took place after August 1980 events. One of the first initiatives of the Independent Self-governing Trade Union "Solidarity" establishing itself in Poznań was to erect a monument commemorating Poznań June 1956.

www.city.poznan.pl/mim/strony/czerwiec56