In the year 1359, the Galeazzo II Visconti conquered the city of Pavia, which became his base of operations. Those who were exiled from Pavia prior to the Visconti conquest were allowed to return and they were granted political amnesty. Although the two brothers had agreed on sharing authority in Milan, Galeazzo's absence from the city allowed his brother Bernabò to possess complete authority over the city. In 1361, Galeazzo II was also able to officially establish a university in Pavia due to a charter that was granted to him by Emperor Charles. Galeazzo II had also married off his son Gian Galeazzo to Isabella of Valois, who was the daughter of the King of France. Galeazzo II also helped his own son acquire political power through a marriage with the French princess Isabella of Valois, which granted his son the title Count of Vertus. On August 4, 1379, Galeazzo II Visconti died, leaving Bernabò as the last of the three co-ruling brothers of Milan. Bernabò would live until 1385 when he was thrown in jail due to a conspiracy hatched by Galeazzo II Visconti's son, Gian Galeazzo Visconti. Gian Galeazzo succeeded his father and became the signore of all the lands that were controlled by his father.