First edition. The liberal statesman and prime minister, sportsman, and historian Archibald Primrose, 5th Earl of Rosebery (1847-1929) was a noted bibliophile, whose discriminating connoisseurship and wealth enabled him to assemble a remarkable library. This library was housed in a number of properties, including Barnbougle Castle and Mentmore Towers, and, after his death, a number of sales of works from his library were held by Sotheby’s in the twentieth and twenty-first centuries. The present catalogue of some 132 lots comprises a broad range of books and manuscripts in English, many from notable libraries – including those of John Dee, Mary of Modena, Edmund Burke, George IV, Sir Mark Masterman Sykes, Bt, and Frederick North, Earl of Guildford – and the highest price achieved in the sale was for a series of some 20 letters from Byron to his friend Francis Hodgson, which sold for £277,250. The catalogue is preceded by an introductory essay by the historian Andrew Roberts and is followed by indices of provenances and authors.