He was the son of Mr. H. Mavin, of 5, Addycombe Cottages, Rothbury.
Morpeth Herald 02/11/1917 carries a brief obituary:
Lance-Corporal J[ohn] R[obert] Mavin, son of Mr and Mrs Mavin, Addycombe Cottages, Rothbury, has died from wounds.
He is remembered at Rothbury on R24.01 R24.02 R24.04 and R24.16