Lieutenant Duncan Stuart Ross Macpherson was the only son of Major General Sir William Grant Macpherson and his American wife, Elizabeth Anne Clunas. He attended Westminster for just a year before leaving for Fettes College in Edinburgh where his father had been educated. After training at Sandhurst, Duncan became a member of the Indian Army, subsequently being attached to the 2nd Battalion the Black Watch. He was then posted to the 7th Gurkha rifles in Quetta Imperial Garrison, near the Afghan frontier. Father and son were clearly close. His father, Sir William, requested and received an appointment as Assistant Director of Medical Services to the 4th Quetta Division, taking his wife with him.

On the outbreak of war Duncan was on home leave so was immediately attached the 8th Battalion Black Watch, as assistant adjutant. Early in November 1914 he was transferred to the 8th Gurkha Rifles, in France. He died with them leading a successful counterattack to reclaim lost trenches on the night of the 23rd November 1914. He was in command of the leading company at the centre of the counterattack at the time. He was unmarried and had previously passed the examinations to promotion to Captain with distinction.

He had spoken to his father only a few hours prior to his death. William never spoke again about the death of his only son. He continued to serve during the war and afterwards wrote the official medical history of World War One.