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.
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. Vol. mdviii. Letters from: 1. His uncle, George Spencer, known as Father Ignatius, Superior of the Order of Passionists in London; 1858-1863. 2. His aunt Frances, Dowager Lady Clinton; 1851-1872, n.d.
Althorp Papers. Vol. mdix. Letters from: 1. His aunt, Isabella, Marchionness of Exeter; 1851-1874. 2. Brownlow Cecil, 2nd Marquess of Exeter and husband of Lady Isabella. Includes a copy of a reply from Spencer; 1851, 1860-1866.
Althorp Papers. Vols. mdx, mdxi. Letters from Spencer's cousin, William Alleyne Cecil, firstly as Lord Burghley, then from 1867 as 3rd Marquess of Exeter. Also included are copies of occasional replies by Spencer; 1857-1889. Two volumes.