David Erskine was educated at Harrow, and joined the army (51st King's Own Light Infantry) as an ensign in 1835 seeing service in India, Malta and Australia. He was appointed Visiting Magistrate in Cleveland, Tasmania in June 1839, at Green Ponds from November 1840 to March 1843, and then moved to Hobart.
He was promoted to Captain in 1845 and left Tasmania in 1846 for India. He was promoted to Major in 1855 and in 1858 he left the army by selling his commission. He next became Colonial Secretary of Natal colony until 1875. He was Resident Magistrate in Walvis Bay, Damaraland (Namibia), from 1878-1880. After retirement he returned to England with his family and was employed ordering the Natal archives. He died in 1903.