Louis's ally, in August 1361. Fearing the formation of a coalition along the western borders of Hungary, Louis asked his former enemy, Louis of Taranto (Joanna I's husband), to send at least one of his brothers to Buda, and mediated a reconciliation between Rudolph IV and the patriarch. At a meeting with Louis's envoys in Prague, Emperor Charles made an insulting remark about Louis's mother, stating that she "was shameless", according to Jan Długosz's chronicle. Louis demanded an apology, but the emperor did not answer. In preparation for a war against Bohemia, Louis ordered the mobilization of the royal army and marched to Trencsén (now Trenčín in Slovakia). However, his supposed allies (Rudolf IV of Austria, Meinhard III of Tyrol and Casimir III of Poland) failed to join him, and the emperor initiated negotiations that lasted for months with the mediation of Casimir III. Louis was finally reconciled with Charles IV at their meeting in Uherské Hradiště on 8 May 1363. Louis invaded Bosnia from two directions in the spring of 1363. An army under the command of Palatine Nicholas Kont and Nicholas Apáti, Archbishop of Esztergom, laid siege to Srebrenica, but the fortress did not surrender. As the royal seal was stolen during the siege, a new seal was made and all Louis's former charters were to be confirmed with the new seal. The army under Louis's personal command besieged Sokolac in July, but could not capture it. Hungarian troops returned to Hungary in the same month. Pope Urban V proclaimed a crusade against the Muslim powers of the Mediterraneum upon Peter I of Cyprus's request on 31 March 1363. Urban V urged Louis to join the crusade, emphasizing that he was a powerful monarch, a devout Christian, and "well-placed to help". The next month the pope levied a three-year tithe on the church revenues in Hungary and asked Louis to support the papal officials to collect the tax. However, Louis made every effort to hinder the activities of the papal tax collectors, stating that he needed resources to cover the costs of his future wars against the infidels and the pope's enemies in Italy. Louis signed a treaty with Emperor Charles and Rudolf IV of Austria in Brno in early 1364, which put an end to their conflicts. In September, Louis visited Cracow to attend the large congress where Peter I of Cyprus attempted to persuade a dozen