Basic Details Surname Cookson Forenames Mostyn Eden Gender Male Information stated on memorial War First World War (1914-1918) Served or died Died Primary Service As stated on memorial Unit (Primary - Stated) Royal Sussex Regiment Rank / Title (Primary - Stated) Major Our References Service (Primary - Our reference) British Army Unit (Primary - Our reference) The Royal Sussex Regiment Rank / Title (Primary - Our reference) Major Death and Burial details Country of death France Town of death Battle of the Aisne Year of death 1914 Month of death September Day of death 14 Age at death 46 Manner of death as stated Killed in Action Manner of death reference Killed in Action