Wirich IV. and his wife M.v.Leiningen
Oberstein Castle inherited a library, founded by Wirich IV. of Daun-Oberstein (1415-1501). In a time where almost no German counts were interested in collecting books, this approach was remarkable. Wirich, being a well educated and well-read humanist, encouraged his young friend Count of Manderscheid-Blankenheim to follow him in collecting books and bibliophilic treasures. This was the origin for the famous Blankenheim Castle Library, which assimilated the vast majority of books from Oberstein and turned out to be one of the largest noble book collections in the German-language area.