Abstract Political celebrations in Lublin in the light of the manuscript and press collections of the Hieronim Łopaciński Provincial Public Library Summary The 440th anniversary of the signing of the Lublin Union, especially significant in terms of the polish national history as well as the history of the Lublin Region, will be celebrated in the year 2009. In this connection it is important to spread knowledge of the manuscript and press cuttings collection in the Hieronim Łopaciński Provincial Public Library which made documentations on the preparation for the 350th-year commemoration of the Union celebrated in Lublin in 1919. Measures taken in connection with the preparation for the anniversary were reconstructed on the basis of the contents in the following belonging to the manuscript collection of the Lublin Library: Manuscripts in the H. Łopaciński Provincial Public Library in Lublin catalogue number 1886. Materials gathered by Henryk Wiercieński "350th anniversary of the Lublin Union 1569. Lublin 1918/19". The publication also includes the description, based on news coverage by the local press, of the celebrations on 1 VII 1919. Political issues and press reports pertaining to the Polish-Lithuanian border conflict between 1919 and 1920 were covered. The materials presented were collected by a Lublin political activist and columnist associated with the National Democracy of Henryk Wiercieński (1843-1923).