Our purpose is to reflect on the role of the ruler of the ruler in the organization and consolidation of the University, in the Portuguese kingdom, in the medieval autumn. We recover a set of political measures taken by the regent Infante D. Pedro (1392-1449) between the years 1441 to 1444 that aimed to protect the lives of men of knowledge and instituted privileges that ensured exclusive dedication to university activities. At the same time, the regent defined measures aimed at the general population so that they would recognize the importance of university men for society. We used as sources a set of eight Letters published in the Chartularium Universitatis Portugalensis that will be analyzed according to the principles formulated by Social History, especially from the concept of long duration of Braudel (1991). We also note, in terms of final considerations, that we believe it is fundamental that the actions of the Portuguese ruler were consciously inclined to defend the existence of the University and its actors.