It moved and astonished the Pope not a little that the Chancellor should attempt to exact an oath of obedience and payment of money from the masters, and, in the end, that official was (p. 043) compelled to give up his claim to demand fees or oaths of fealty or obedience for a licence to teach, and to relax any oaths that had already been taken. The masters, as Dr Rashdall points out, already possessed the weapon of boycotting, and ordering their students to boycott, a teacher upon whom the Chancellor conferred a licence against the wish of their guild, but they could not at first compel him to grant a licence to anyone whom they desired to admit. After the Papal intervention of 1212, the Chancellor was bound to licence a candidate recommended by the masters. In the account of their own history, from which we have already quoted, the Parisian masters speak of their venerable "gignasium litterarum" as divided into four faculties, Theology, Law, Medicine, and Philosophy, and they compare the four streams of learning to the four rivers of Paradise. The largest and most important was the Faculty of Arts, and the masters of that Faculty were the protagonists in the struggle with the Chancellor, a struggle which continued long after the intervention of Innocent III. In the course of this long and successful conflict, the Faculty of Arts developed an internal organisation, consisting of four nations, distinguished as the French, the Normans, the Picards, and the English. Each nation elected a proctor, and the four proctors or other representatives of the (p. 044) nations elected a Rector, who was the Head of the Faculty of Arts. The division into nations and the title of Rector may have been copied from Bologna, but the organisation at Paris was essentially different. The Parisian nations were governed by masters, not by students, and whereas, at Bologna, the artists were an insignificant minority, at Paris, the Rector became, by the end of the thirteenth century, the most powerful official of the University, and, by the middle of the fourteenth, was recognised as its Head. The superior Faculties of Theology, Canon Law, and Medicine, though they possessed independent constitutions under their own Deans, consisted largely of men who had taken a Master's or a Bachelor's degree in Arts, and, from the middle of the thirteenth century, they took an oath to the Rector, which was held to be binding even after they became doctors. The non-artist members of these Faculties were not likely to be able to resist an authority whose existence was generally welcomed as the centre of the opposition to the Chancellor. Ultimately, the whole University passed under the sway of the Rector, and the power of the Chancellor was restricted to granting the _jus ubique docendi_ as the representative of the Pope. Even this was little more than a formality, for the Chancellor "ceased," says Dr Rashdall, "to have any real control over