Two main theories have been advanced to account for the rise of a "studium generale" at Oxford. One group of writers[405] connects its origin with some one or other of the conventual schools at Oxford. By analogy with the origin of the European universities which are considered "primary," they suggest that the Church was the foster-mother of the university, and that the earliest schools were those in connection with St. Frideswide and the abbeys of Oseney and Eynesham. The other theory (advanced by Rashdall) connects the rise of a university at Oxford with a migration from Paris, which is supposed to have occurred in or about the year 1167. In support of this hypothesis it is pointed out that about that date Henry II. (who was then engaged in a conflict with his Archbishop, Thomas Becket) required "that all scholars be compelled to return to their country or be deprived of their benefices."[406] Rashdall also points out that from this time onwards we hear of sermons being preached expressly for "clerkes from various parts of England."[407] Both of these theories are open to objections. The evidence in favour of a migration is based upon a series of assumptions; if a migration of this character really occurred it is difficult to account for the silence of all the English chroniclers on an event which must have appealed to the imagination; no record is available of any clerk who left Paris on account of the edict, or of any clerk going from Paris to Oxford. On the other hand, it must be admitted that the theory of gradual development is also open to objection. It is vague and indefinite as to details of the growth of the "studium generale"; no authoritative explanation is given for the independent position of the early Oxford masters, and for their freedom from all immediate ecclesiastical control. The question of the relationship of the university to the Church needs careful consideration. A great deal depends upon the account of the origin of the university which is accepted. If it is maintained, that from the time of its origin, it was under ecclesiastical supervision, then it is difficult to account for the spirit of independence which was manifested during the period that immediately preceded the Legatine Ordinance of 1214. However, by that ordinance ecclesiastical control was definitely asserted; the scholars were made subject to the jurisdiction of the Church, and the position of chancellor was established--probably to mark the subjection of the masters to episcopal control.[408]