This paper offers a contribution to the history of historiography on the University of Pavia. The Author takes into account both the treaties explicitly dealing (since the 18th Century) with the history of the University, but also all the evidence of a historical consciousness about the origins and history of the University; such a historical consciousness started to appear in 1361, when the Visconti Family officially founded the University. Particular attention is paid to the three interpretations about the foundation (origo), which has been attributed to the Lombard Kings, to Charlemagne and to Lothair I. For a long time there was a widespread belief in Europe that the University of Pavia had been founded by Charlemagne, simultaneously with the University of Paris; the creator of this tradition (based on the history of Charlemagne written by Notker the Stammerer) was Barthélemy de Chasseneuz, in 1525. The attribution of the founding to Lothair in 825 is only a recent idea, which has been nourished, with different intentions, by the 19th Century German legal historians who discovered a school of Lombard Law in Pavia (attested since at least the 10th Century) and by the Celebrations held in Pavia in 1925.