CASTLE LIBRARY OF OTTO JR. OF NOSTITZ IN JAWOR The library of Otto Jr. of Nostitz was founded in the beginning of the 1650's in the Lower Silesian castle Jawor. It consists approximately of 5 000 volumes and its structure as well as its history makes it unique and elevates the Jawor library among the most interesting book collections of early modern Europe. Shortly after death of its founder, the library was bought by Otto's brother Johann Hartwig of Nostitz and moved to the newly built palace in Malá Strana in Prague where it laid the foundations of the new family library of the house of Nostitz. The library is placed in two rooms on the second floor till today. The thesis tries to introduce the personality of the founder of the Jawor library Otto Jr. of Nostitz, his tastes in the book purchase as well as the topical structure of his book collection and its future fates. Notwithstanding, the main point of the doctor thesis is to present the issues of the thorough provenance research of the oldest part of the library. The terminus ante quem for the year of edition of the books relevant for the provenance research marks out the death of Otto Jr. in the year 1665. The most recent and complete catalogue of the Nostitz library in the present use dates back to the 19th century and shows remarkable leaks and...