In Norham St. Cuthbert's Churchyard is a family headstone for Sanderson which includes:
William Sanderson
Son of Robert and Mary Sanderson
Killed in action at Gallipoli in the Dardanelles on 12th August 1915, age 35 years
CWGC gives his date of death as July, not August.
Information: Tony Harding
William Sanderson is remembered in Norham on N27.02 and N27.04