This collection consists of a major portion of the library formed over three centuries by members of the Lothian family and formerly housed at Newbattle Abbey. A number of important items from the library were sold in 1932 in New York, but the remainder was bequeathed to the National Library of Scotland by Philip Henry Kerr, 11th Marquess of Lothian (1882-1940), and acquired in 1950. The collection comprises 5,158 printed volumes and 112 manuscripts and is rich in foreign books of the 15th to the 18th century. French and Italian literature and history are well represented in the collection, which includes illustrated books of antiquities, architecture, natural history, geography and topography, as well as maps and atlases. Roller maps from the collection are held in the Map Library.
The manuscripts are described and indexed in Vol. IV of the Library's Catalogue of Manuscripts. NLS MSS.5818-27 are catalogues of the family libraries at Newbattle and in London, 1666-1876. NLS MS.5828 contains letters and papers concerning the family libraries, 1643-1899. Illuminated Manuscripts Incunabula and Americana from the Famous Libraries of the Most Hon. the Marquess of Lothian, C.H. Sold ... January 27 and 28, 1932, New York, 1932. Donald Drew Egbert, The Tickhill Psalter, New York, 1940, 8-10, 128-130.