Eldridge was born in Southampton on 17 May 1936, and as child lived through the blitz on the city during the Second World War. He attended Taunton's School, Southampton and as a schoolboy became the English junior chess champion . He gained a BSc (Econ) from the University of London at the then University College, Leicester and an MA from Leicester University. He was married to Rosemary North in 1960; after her death in 1997, he married Christine Reid in 2006. He was a long-serving Methodist local preacher. Eldridge died on 24 December 2022, at the age of 86.
