that characterized the Italian Middle Ages, Pavia was traditionally Ghibelline, a position that was as much supported by the rivalry with Milan as it was a mark of the defiance of the Emperor that led the Lombard League against the emperor Frederick Barbarossa, who was attempting to reassert long-dormant Imperial influence over Italy. Frederick I celebrated two coronations in Pavia (1155 and 1162) in the basilica of San Michele Maggiore and resieded in a new imperial palace near the royal monastery of St. Salvatore. Several times the Pavia army fought with the emperor against the forces of the Lombard League, participating in the sieges of Tortona, Crema and Milan and in other military operations.The city also had a reputation as a place to have a "good time," as witness the Archpoet's famous comments of 1163. In the following centuries Pavia was an important and active town. Pavia supported the emperor Frederick II against the Lombard League and the Pavese army took part in numerous operations in the service of the emperor and participated in the battle of Cortenuova in 1237. Under the Treaty of Pavia, Emperor Louis IV granted during his stay in Italy the Electorate of the Palatinate to his brother Duke Rudolph's descendants. Pavia held out against the domination of Milan, finally yielding to the Visconti family, rulers of that city in 1359 after a difficult siege; under the Visconti Pavia became an intellectual and artistic centre, being the seat from 1361 of the University of Pavia founded around the nucleus of the old school of law, which attracted students from many countries. During the regency of Galeazzo II and Gian Galeazzo the memory of the capital's role and the Lombard traditions of Pavia jointly entered the “propaganda” of the new masters of the of Pavia: Galeazzo II moved his court from Milan to Pavia and between 1361 and 1365 Galeazzo II built a large palace (Visconti castle) with a major Park (Visconti Park), which became the official residence of the dynasty. In 1396 Gian Galeazzo commissioned the building of the Certosa, built at the end of the Visconti Park, which connected the Certosa to the castle of Pavia. The church, the last edifice of the complex to be built, was to be the family mausoleum of the Visconti. In 1389, by the will of Gian Galeazzo Visconti, some families of German Jews settled in Pavia, mainly active