Polish Canadians typically identify themselves as stringent anti-Communists, a label solidified by the legacies of the 1980s Solidarity movement, its founder Lech Walesa, and the widespread anti-Communist riots that helped topple the Communist regime in 1989. Hurrah Revolutionaries challenges this common perception by examining the Polish immigrant community in Canada and the development of radical and traditionally "deviant" ideologies during the interwar period until the end of the Second World War. Patryk Polec unveils a versatile, well-funded, and influential Polish pro-Communist movement with a talented leadership that worked tirelessly to persuade traditionally conservative and religious immigrants to adopt an ideology that was anti-nationalist and atheist. He traces the roots of socialist support in Poland, its transplantation to Canada where the movement enjoyed its greatest support, the challenges the movement faced within an ethnic community influenced by Catholicism, and the complications caused by its links to the Communist International. Polec offers a deeper understanding of the ways in which the Communist Party was able to appeal to certain ethnic groups through cultural outreach as well as its complicated and often counter-productive relationship with the Soviet Union. Grounded in recently declassified Polish consular documents and RCMP surveillance reports, Hurrah Revolutionaries is the first full-length study of Polish Communists in Canada, a group that constituted a substantial portion of the country's socialist left in the twentieth century.