Louis marched to Naples in February. The citizens offered him a ceremonious entry, but he refused, threatening to let his soldiers sack the town if they did not raise the taxes. He adopted the traditional titles of the kings of Naples – "King of Sicily and Jerusalem, Duke of Apulia and Prince of Capua" – and administered the kingdom from the Castel Nuovo, garrisoning his mercenaries in the most important forts. He used unusually brutal methods of investigation to capture all accomplices in the death of his brother, according to Domenico da Gravina. Most local noble families (including the Balzos and the Sanseverinos) refused to cooperate with him. The pope refused to confirm Louis's rule in Naples, which would have united two powerful kingdoms under Louis's rule. The pope and the cardinals declared Queen Joanna innocent of her husband's murder at a formal meeting of the College of Cardinals.