The extent, contents and cultural- and scientific significance of the Auersperg family‘s Ljubljana library, which was at its peak at the of the brothers Wolf Engelbert (1610–1673) and Joannes Weickhard (1615–1677), is only known from individual catalogues, inventories and censuses, as the collection has been dispersed. Until recently, only the 1668 catalogue, and its transcription from 1762, have been known, but in the course of researches in the Auersperg family archives in Vienna five additional library catalogues and inventories from the 17th and the 18th centuries were discovered. The article presents basic information about the already known, as well as the newly discovered, early catalogues and inventories, which reveal the continuity and characteristics of this comprehensive collection’s development through time. It also presents both catalogues from London auctions in the 1980s, where more than 800 of the Auersperg library’s books were sold.

The extent, contents and cultural- and scientific significance of the Auersperg family‘s Ljubljana library, which was at its peak at the of the brothers Wolf Engelbert (1610–1673) and Joannes Weickhard (1615–1677), is only known from individual catalogues, inventories and censuses, as the collection has been dispersed. Until recently, only the 1668 catalogue, and its transcription from 1762, have been known, but in the course of researches in the Auersperg family archives in Vienna five additional library catalogues and inventories from the 17th and the 18th centuries were discovered. The article presents basic information about the already known, as well as the newly discovered, early catalogues and inventories, which reveal the continuity and characteristics of this comprehensive collection’s development through time. It also presents both catalogues from London auctions in the 1980s, where more than 800 of the Auersperg library’s books were sold.