The University of Oxford has no known foundation date. Teaching at Oxford existed in some form in 1096, but it is unclear at what point a university came into being.
The expulsion of foreigners from the University of Paris in 1167 caused many English scholars to return from France and settle in Oxford. The historian Gerald of Wales lectured to such scholars in 1188, and the first known foreign scholar, Emo of Friesland, arrived in 1190. The head of the University was named a chancellor from at least 1201, and the masters were recognised as a universitas or corporation in 1231. The students associated together on the basis of geographical origins, into two "nations", representing the North (including the Scots) and the South (including the Irish and the Welsh). In later centuries, geographical origins continued to influence many students' affiliations when membership of a college or hall became customary in Oxford. Members of many religious orders, including Dominicans, Franciscans, Carmelites, and Augustinians, settled in Oxford in the mid-13th century, gained influence, and maintained houses for students. At about the same time, private benefactors established colleges to serve as self-contained scholarly communities. Among the earliest such founders were William of Durham, who in 1249 endowed University College, and John Balliol, father of a future King of Scots: Balliol College bears his name. Another founder, Walter de Merton, a chancellor of England and afterwards Bishop of Rochester, devised a series of regulations for college life; Merton College thereby became the model for such establishments at Oxford, as well as at the University of Cambridge. Thereafter, an increasing number of students forsook living in halls and religious houses in favour of living in colleges.