Having already collected about 1,500 manuscripts during the first two and a half centuries of its existence, the Munich Court Library was turned into the largest collection of manuscripts in the German language are by the integration of the Mannheim court library and of the holdings of the Bavarian monastic libraries at the beginning of the 19th century . Its holdings had suddenly increased fifteen-fold. The classification and cataloguing of the huge amount of manuscripts is owed to the librarian Johann Andreas Schmeller, who is known as a philologist, and whose repertories of the Latin and German manuscripts served as the basis of the catalogues which were printed from 1866 or 1868 onward.

The further course of the 19th century brought enormous further increases of the holdings, particularly as a consequence of the sea-change of the library landscape at its beginning. Since then, the development continued constantly through the purchase of complete collections; a purposeful acquisition policy with a broad scope served the sophistication and completion of the collection.