Henry Duncan Littlejohn son of a baker was born in Leith Street, Edinburgh, Scotland in 1826. Educated at Perth Academy, Edinburgh High School and the University of Edinburgh he became a lecturer at the extra-mural School of Medicine at Surgeons Hall in 1854.

Due to overcrowding and lack of sanitation, cholera, typhoid, diptheria and smallpox continued to cause a high proportion of deaths among the lower classes in Scotland's town and cities during the Victorian period. Dr. Littlejohn's report on the city's sanitary conditions published in 1865 provided the authorities with a plan to tackle the problem.

Taking his advice Edinburgh Town Council began demolishing the city's slum properties which were a breeding ground for disease. The hard working surgeon died at Benreoch, Arrochar in 1914. His ashes were brought back to his birthplace and interred in the Dean Cemetery.