Was a theological student at the Regent's Park College, and, with the object of becoming a medical missionary, simultaneously entered the Middlesex Hospital Medical School, where he was first Brodrip Scholar and Prizeman, and after graduating at the University of London acted as House Surgeon to Sir Alfred Pearce Gould (qv). Having become FRCS he went out in October, 1909, to the English Baptist Mission at Sian Fu, the capital of the province of Shensi, North China, as the colleague of Stanley Jenkins (qv). In 1911 Jenkins returned home on furlough, and Robertson was in charge of the hospital when the Revolution broke out and some 15,000 Manchus were slaughtered in Sian Fu on October 22nd, 1911, their heads being exposed on the city walls. Other missionaries had withdrawn to the coast, but Robertson remained. He replied to the request to organize ambulances, and through scenes of the utmost horror he worked with skill, performing many operations successfully whenever the prejudices of the people did not prevent him. The Chinese authorities marked their gratitude when the Army presented him with a tablet containing a laudatory address, and the populace presented him with a red silk umbrella. In addition he operated successfully on a fellow-missionary for appendicitis, and shortly before his death he went a six days' ride to visit the child of a missionary. He had contracted typhus fever from his out-patients, in which he was attended and nursed by his elder colleague, Stanley Jenkins, but he died on March 16th, 1913. He was a manly, skilled Christian medical missionary. Typhus fever carried off James Glenny Gibb (qv) in 1912, and Stanley Jenkins succumbed to it in the month following Robertson's death - April, 1913. They may be justly regarded as martyrs to the highest form of duty. Chinese officials and soldiers alike recognized his work. Robertson had organized a Corps of Bearers and Nurses to care for the wounded, and so originated a Red Cross League in China. He also persuaded the Governor of the Province to institute a Hospital for Disabled Soldiers, styled 'Robertson's Pensioners'. The Military Governor accorded him a full military funeral; his 'Pensioners' provided a white silk pall for his burial; the military carried banners inscribed with the words, "He created happiness throughout the Province of Shensi." At the funeral service the Governor, who had not been in sympathy with the Mission and its work, used words as follows, "No doubt he was God's servant."