Kay (Kaj) Just Ditlevsen was born on 29 March 1887 in Copenhagen, Kobenhavn, Denmark. His father, Johan, was 31 and his mother, Dagmar, was 24.
He had one daughter with Gertrude Mabel Lancaster in 1917. He lived in Hull and enlisted in Hull. Served in the Army Service Corps, Clearing Office (Blackheath).
He died as a young father on 17 September 1918 in United Kingdom, at the age of 31. Buried Hull Western Cemetery.
He was Nephew of Mrs. D. Ditlevsen, of 23, Stesnegade, Copenhagen, Denmark.