The first half of the thirteenth century witnessed the foundation of these _studi_ in considerable numbers. That of Vercelli was opened in 1228, the municipality providing two certified copyists for the convenience of students who might wish to purchase text-books.[76] In 1224 the Emperor Frederick II., to whom the south of Italy owed a precocious eminence in literature, established the University of Naples by an Imperial diploma.[77] With a view to rendering it the chief seat of learning in his dominions, he forbade the subjects of the Regno to frequent other schools, and suppressed the University of Bologna by letters general. Thereupon Bologna joined the Lombard League, defied the emperor, and refused to close the schools, which numbered at that period about ten thousand students of various nationalities. In 1227 Frederick revoked his edict, and Bologna remained thenceforward unmolested. Political and internal vicissitudes, affecting all the Italian universities at this period, interrupted the prosperity of that of Naples. In the middle of the thirteenth century Salerno proved a dangerous rival; but when the House of Anjou was established in the kingdom of the Sicilies, special privileges were granted, restoring the high school of the capital to the first rank. Charles I. created a separate court of jurisdiction for its management. This consisted of a judge and three assessors, one for the control of foreigners, another for the subjects of the Regno, and the third for Italians from other states. [Footnote 76: They were called 'Exemplatores.' See Tiraboschi, vol. iv. lib. i cap. 2.] [Footnote 77: Muratori, vii. p. 997. Amari, _Storia dei Mussulmani di Sicilia_, vol. iii. p. 706.]