Althorp Papers. Vols. mdxxiii, mdxxiv. Correspondence with Horace Seymour, brother of Charlotte Spencer. For letters to Spencer from Seymour in his capacity as private secretary to Gladstone see below; 1863-1901. Two volumes.
Althorp Papers. Vols. mdvi, mdvii. Correspondence with his half sister Victoria (Va) and her husband William, 2nd Baron Sandhurst. Most of the letters are written by Sandhurst; 1866-1910. Two volumes.
Althorp Papers. Vols. mdxvi, mdxvii. Correspondence with and relating to Spencer Lyttelton, brother of George William, 4th Baron Lyttelton. Many of the letters and accompanying papers relate to family attempts to extricate Spencer Lyttelton from financial and other troubles; 1857-1889. Two volumes.
Althorp Papers. Vol. mdxxvii. Letters from Frederick Beauchamp Paget Seymour, later Baron Alcester of Alcester, Charlotte Spencer's cousin; 1852-1885, 1894.
Althorp Papers. Vol. mdxxviii. Correspondence with Luke White, 3rd Baron Annaly. Annaly was married to Charlotte Spencer's niece Lilah, daughter of 3rd Viscount Clifden; 1888, 1895-1910, n.d.
Althorp Papers. Vol. mdv. Letters from Margaret (nee Baring), wife of Charles Robert Spencer, and their children, including some by Albert Edward John (Jack), later 7th Earl Spencer; 1883, 1899-1910.