Mary Bateson was born to William Henry Bateson, Master of St. John's College, Cambridge University, and his wife Anna Aikin, a founding member of the Cambridge Women's Suffrage Movement. They were both supporters of higher education for women and helped establish Newnham College at Cambridge. After attending the Misses Thornton's School for young ladies, Mary spent a year studying at the Institut Friedländer in Germany. In 1871, she returned to England and attended the newly-opened Perse School for Girls, where she completed her studies and taught German. In 1884, Mary and her sister Anna both enrolled at Newnham College. Mary graduated with an informal First in history with a dissertation on "Monastic Civilisation in the Fens." She campaigned successfully for the establishment of research fellowships at Newnham and eventually became one of the first fellows of the College in 1903. In 1889 she was appointed as lecturer on English constitutional history. She wrote and edited numerous books, papers, scholarly and popular articles, and was a frequent contributor to the English Historical Review. Among them was Mediaeval England, 1066-1350 (1903). She was a leader in the women's suffrage movement and took the socially unusual step for a single woman of that era of living on her own. She died of a brain hemorrhage in 1906 at age 40.