Markham began his career as a Royal Navy cadet and midshipman, during which time he went to the Arctic with in one of the many searches for Franklin's lost expedition. Later, Markham served as a geographer to the India Office, and was responsible for the collection of cinchona plants from their native Peruvian forests, and their transplantation in India. By this means the Indian government acquired a home source from which quinine could be extracted. Markham also served as geographer to Sir Robert Napier's Abyssinian expeditionary force, and was present in 1868, at the fall of Magdala.