Under the guidance of the new prime minister Prince Schwarzenberg the Third, the new emperor at first pursued a cautious course, granting a constitution in early 1849. At the same time, a military campaign was necessary against the Hungarians, who had rebelled against Habsburg central authority in the name of their ancient constitution. Franz Joseph was also almost immediately faced with a renewal of the fighting in Italy, with King Charles Albert of Sardinia taking advantage of setbacks in Hungary to resume the war in March 1849.