On August 31, 1980, representatives of the communist government of Poland agree to the demands of striking shipyard workers in the city of Gdansk. Former electrician Lech Walesa led the striking workers, who went on to form Solidarity, the first independent labor union to develop in a Soviet bloc nation.

In July 1980, facing economic crisis, Poland’s government raised the price of food and other goods, while curbing the growth of wages. The price hikes made it difficult for many Poles to afford basic necessities, and a wave of strikes swept the country. Amid mounting tensions, a popular forklift operator named Anna Walentynowicz was fired from the Lenin Shipyard in the northern Polish city of Gdansk. In mid-August, some 17,000 of the shipyard’s workers began a sit-down strike to campaign for her reinstatement, as well as for a modest increase in wages. They were led by the former shipyard electrician Lech Walesa, who had himself been fired for union activism four years earlier.

Despite governmental censorship and attempts to keep news of the strike from getting out, similar protests broke out in industrial cities throughout Poland. On August 17, an Interfactory Strike Committee presented the Polish government with 21 ambitious demands, including the right to organize independent trade unions, the right to strike, the release of political prisoners and increased freedom of expression. Fearing the general strike would lead to a national revolt, the government sent a commission to Gdansk to negotiate with the rebellious workers. On August 31, Walesa and Deputy Premier Mieczyslaw Jagielski signed an agreement giving in to many of the workers’ demands. Walesa signed the document with a giant ballpoint pen decorated with a picture of the newly elected Pope John Paul II (Karol Wojtyla, the former archbishop of Krakow).

In the wake of the Gdansk strike, leaders of the Interfactory Strike Committee voted to create a single national trade union known as Solidarnosc (Solidarity), which soon evolved into a mass social movement, with a membership of more than 10 million people. Solidarity attracted sympathy from Western leaders and hostility from Moscow, where the Kremlin considered a military invasion of Poland.

In late 1981, under Soviet pressure, the government of General Wojciech Jaruzelski annulled the recognition of Solidarity and declared martial law in Poland. Some 6,000 Solidarity activists were arrested, including Walesa, who was detained for almost a year. The Solidarity movement moved underground, where it continued to enjoy support from international leaders such as U.S. President Ronald Reagan, who imposed sanctions on Poland. Walesa was awarded the 1983 Nobel Peace Prize, and after the fall of communism in 1989 he became the first president of Poland ever to be elected by popular vote.