It will be observed that the majority of the _studi pubblici_ obtained charters either from the Pope or the emperor, or from both, less for the sake of any immediate benefit to be derived from Papal or Imperial patronage, than because supreme authority in Italy was still referred to one or other of these heads. It was a great object with each city to increase its wealth by attracting foreigners as residents, and to retain the native youth within its precincts. The municipalities, therefore, accorded immunities from taxation and military service to _bona fide_ students, prohibited their burghers from seeking rival places of learning, and in some cases allowed the university authorities to exercise a special jurisdiction over the motley multitude of scholars from all countries. How miscellaneous the concourse in some of the high schools used to be, may be gathered from the reports extracted by Tiraboschi from their registers. At Vicenza, for example, in 1209 we find the names of Bohemians, Poles, Frenchmen, Burgundians, Germans, and Spaniards, as well as of Italians of divers towns. The rectors of this _studio_ in 1205 included an Englishman, a Provençal, a German, and a Cremonese. The list of illustrious students at Bologna between 1265 and 1294 show men of all the European nationalities, proving that the foreigners attracted by the university must have formed no inconsiderable element in the whole population.[79] This will account for the prominent part played by the students from time to time in the political history of Bologna.[80] [Footnote 79: In 1320 there were at least 15,000 students in Bologna.] [Footnote 80: See Sismondi, vol. iii. p. 349.]