Eustace James Anthony Balfour (1854-1912) was the son of James M. Balfour and Lady Blanche Balfour, sister of Robert Cecil, the marquess of Salisbury (1830-1903), and the brother of statesman Arthur James Balfour (1848-1930) and naturalist Francis Maitland Balfour (1851-1882). He became a painter and architect, and designed the rebuilding of the Crown Court church. Balfour's wife, Lady Frances Balfour (1858-1931), was the daughter of George Douglas Campbell, the eighth Duke of Argyll (1823-1900). Her brother, John Douglas Sutherland Campbell, the ninth Duke of Argyll (1845-1914), was married to Princess Louise (1848-1939), the daughter of Queen Victoria (1819-1901). Lady Balfour was active as a churchwoman, suffragist and author.
From the description of Letters of Eustace James Anthony Balfour, 1854-1937 (bulk 1880-1914). (Huntington Library, Art Collections & Botanical Gardens). WorldCat record id: 122545610