Claude G. Southey was the only son of Charles W. Southey, senator and farmer, and his wife Georgina S.M. Greaves. He was a grandson of Sir Richard Southey*. In 1893 he presented a variety of prehistoric stone artefacts from the Cradock district to the Port Elizabeth Museum. Years later, in 1905, he donated "stone knives and flakes" from the Middelburg Division to the South African Museum, Cape Town. In 1923 he published a pamphlet entitled The conservation of flood waters (Cape Town, 5p), which was written in both English and Afrikaans.