Dorothy Hartley was the youngest of three children of the headmaster of Ermysted's Grammar School, Skipton, Yorkshire, where she was born. She was educated at another school, a convent run by French nuns in Skipton until 1904, when her father, the Rev. Edward Hartley, became rector of a parish in Nottinghamshire. She completed her secondary education at Loughborough High School and attended Nottingham Art School. During World War I, she took a break from her studies to work in a munitions factory. In 1919, she entered the Regent Street Polytechnic in London, where she was a prize pupil. She returned to Nottingham Art School as a teacher in 1920 and continued to teach there and at other schools, including University College and Goldsmiths' College. Miss Hartley began writing in her spare time while working as an art teacher. She traveled widely, taking photographs that were later exhibited at the Imperial Institute in London, and writing articles for The Daily Sketch. In 1933, Miss Hartley moved to a house in Froncysyllte, Wales, her mother's native village, where she lived for the rest of her life. Her books were acclaimed for their scholarship, enjoyment of her subjects, and richly detailed descriptions of life in the modern or medieval world. Miss Hartley appeared on television with the chef Philip Harben and advised on the BBC show The Archers.