Polish underground press, devoted to prohibited materials (sl. , lit. semitransparent blotting paper or, alternatively, , lit. second circulation), has a long history of combatting censorship of oppressive regimes in Poland. It existed throughout the 19th and 20th centuries, including under foreign occupation of the country, as well as during the totalitarian rule of the pro-Soviet government. Throughout the Eastern Bloc, bibuła published until the collapse of communism was known also as samizdat (see below). Partitions of Poland In the 19th century in partitioned Poland, many underground newspapers appeared; among the most prominent was the Robotnik, published in over 1,000 copies from 1894. World War II In the Second World War, in occupied Poland there were thousands of underground publications by the Polish Secret State and the Polish resistance. The Tajne Wojskowe Zakłady Wydawnicze (Secret Military Printing Works) was probably the largest underground publisher in the world. The Home Army Biuletyn Informacyjny reached an estimated circulation of 47,000. Polish People's Republic In the Polish People's Republic during the 1970s and 1980s, several books (sometimes as long as 500 pages) were printed in quantities often exceeding 5,000 copies. In 1980 and 1981, during the short legal existence of Solidarity trade union, actual newspapers were also published. Most of the Polish underground press was organized in the 1970s by the Movement for Defense of Human and Civic Rights (ROPCiO) and Workers' Defence Committee (KOR). Over several years, alongside hundreds of small individual publishers, several large underground publishing houses were created, fueled by supplies smuggled from abroad or stolen from the backrooms of official publishing houses. Throughout the communist era, Poland's Catholic Church and some Christian organizations and groups were allowed to publish a number of periodicals with a certain amount of freedom and a more or less clear anti-communist stand in various periods - but censored. The weekly Tygodnik Powszechny, half openly supporting KOR since 1976 and Solidarity since 1980, and monthly Więż were among the most popular. A news-sheet Solidarność, printed in the Gdansk shipyard during the August 1980 strike, reached a print run of 30,000 copies daily. The communist regime then allowed for two legal periodics to be published under the government control and censorship, yet with a significant margin of freedom: in January 1981, a regional weekly Jedność in Szczecin, and in May the nationwide weekly Tygodnik Solidarność with Tadeusz Mazowiecki as chief editor and circulation of 500,000. Both