Maxwell, Constantia (Elizabeth) (1886–1962), historian, was born in Dublin, the daughter of Patrick Maxwell, a distinguished Scottish ophthalmic surgeon, who came to Dublin from Scotland in 1884, when he was appointed assistant surgeon to the National Eye and Ear Infirmary. Constantia, educated at St Leonard's, a progressive girls' school in St Andrews, Scotland, and her sister Euphan Maxwell (1887–1964), later a surgeon at the Royal Eye and Ear Hospital, Dublin, were among the first group of women who entered TCD as students in 1904. As an undergraduate Euphan was a founder committee member of the Elizabethan Society, formed by the college's female students in 1905. A brilliant student, Constantia graduated BA with a gold medal in 1908, then spent a year at Bedford College, London, where she made valuable contacts in English academic life. On her return to Dublin she was appointed lecturer in modern history at TCD in 1909, becoming the first woman to join the college's academic staff. She received an MA in 1911, and became an assistant to the professor; in 1939 she became the college's first woman professor (economic history), and in 1945 she succeeded to the Lecky professorship of modern history, becoming the first woman to hold an established full-time chair.
After the publication of her first book, A short history of Ireland (1914), she reached a wide public in 1923 with her next work, Irish history from contemporary sources. This was followed by significant editions of Arthur Young's Tour of Ireland (1925) and Young's travels in France (1929), and The English traveller in France, 1649–1815 (1932). However, it was with Dublin under the Georges (1936; repr. 1956) and Country and town in Ireland under the Georges (1940), two pioneering studies of eighteenth-century Irish society, that she earned both academic and popular acclaim. Their publication marked the high-points of her career, and further consolidated her reputation as one of the foremost scholars of her generation. Among her later publications were A history of Trinity College, Dublin, 1592–1892 (1946), an anthology of the writings of Samuel Johnson (1948), and The stranger in Ireland, from the reign of Elizabeth to the Great Famine (1954). She was appointed to the Irish Academy of Letters in 1953. Politically conservative, Maxwell's writings placed her firmly within the established tradition of Anglo-Irish historiography. Inevitably she came in for criticism from Irish nationalists, who accused her of bypassing the position of the native Catholic populace in favour of a detailed examination of the English ruling elite.
A rather distant, aloof woman (undergraduates remembered her for her ‘amused and ironic detachment which extended itself to all human affairs’, Trinity, p. 35), she shared a home for many years with her sister at Lower Baggot Street. Both enjoyed regularly entertaining friends in the Haughton House at Dublin zoo, where they ritually fed their pet vultures. On her retirement in 1951 she moved to Cranbrook, Kent. She died in nearby Pembury on 6 February 1962.