Another book collection which now belongs to Cieszyn Library is a private legacy. It is the library of Tadeusz Reger (1872-1938), a politician who spent most of his life in Cieszyn Silesia, where he played a key role in the socialist and independence movement. Unfortunately, the book collection of Tadeusz Reger which is stored in Cieszyn is incomplete. When its owner died, his most valuable collectibles were given to the Central Archive of the Polish Socialist Party and to the Józef Piłsudski Museum in Łódź. The Museum in Cieszyn managed to buy only a part of the legacy left by Tadeusz Reger. The purchased collection was divided into two groups. One of them is the book collection, whereas the other is made up of archive materials, referred to as the Reger Files. The book collection includes 7,000 volumes. There are mostly works devoted to history, law, sociology, nature and silesiaca. The archives, which consist of 5,500 bibliographic records, are much more valuable. Archive materials include documents and official files, notes, correspondence, newspaper clippings, ephemera, etc. They are directly related to Tadeusz Reger or to people, organizations and institutions that he cooperated with, kept in touch with or in whose activities he was interested. In total, they are an invaluable source base for studying the history of Cieszyn Silesia from the 1890s to 1938.