In 1901, it was granted the Royal warrant of appointment as booksellers and bookbinders to King Edward VII, renewed by George V in 1910.

[1] In 1892, Sotheran's managed to secure Althorp’s complete library, including its very rare collection of Caxtons, for £210,000 (equivalent to almost £33.5 million in 2024); the collection was sold to Enriqueta Augustina Rylands, who erected in Manchester a permanent memorial of her husband in the John Rylands Library.

[2] In 1896, Sotheran's sold to J. P. Morgan a Gutenberg Bible on vellum, for £2,750, and an even more expensive collection of Byron manuscripts; the following year, it secured the Warwick Castle Shakespeare Library for Henry Clay Folger.

English bookseller and Charles Dickens scholar John Harrison Stonehouse joined the firm as an apprentice in 1884.

[7] In 1909, Stonehouse commissioned the bookbinders Sangorski & Sutcliffe to produce the famous jewelled copy of Edward FitzGerald's The Rubaiyat of Omar Khayyam, lost with the Titanic in 1912.