Alfred Walter Stewart, who wrote under the pen name J. J. Connington, was born in Glasgow, the youngest of three sons of Reverend Dr Stewart. He graduated from Glasgow University and pursued an academic career as a chemistry professor, working for the Admiralty during the First World War. Known for his ingenious and carefully worked-out puzzles and in-depth character development, he was admired by a host of his better-known contemporaries, including Dorothy L. Sayers and John Dickson Carr, who both paid tribute to his influence on their work. He married Jessie Lily Courts in 1916 and they had one daughter.