The core of resources belonging to Cieszyn Library are historic book collections, namely Leopold Jan Szersznik’s library, the People’s Library, the Library of the Polish Ethnological Society, Tadeusz Reger’s library, the Former Museum’s Library and Józef Ignacy Kraszewski’s library. Apart from the last one, all of these collections were created in Cieszyn between the second half of the 18th century and the beginning of the 20th century. Their history is intertwined with the history of the town and the whole region. In fact, this relation is much older than the libraries themselves because most of the abovementioned repositories include fragments or remains of institutional and private collections whose creation and presence in Cieszyn sometimes date back to the Middle Ages.
The abovementioned libraries ceased to be independent in the 1920s and 1930s, when they were merged and stored in the City Museum. In 1960, they became the foundation of the Historic Branch of the Silesian Library which was established in Cieszyn. In 1988, the Historic Branch was incorporated into the City Public Library, and six years later it became the foundation for establishing the independent Cieszyn Library (Książnica Cieszyńska).