Upon the pope's request, Louis sent Hungarian troops to relieve Bologna, which was besieged by Bernabò Visconti's troops. After Visconti lifted the siege, Louis's mercenaries pillaged the region and refused to cooperate with the papal legate; Louis had the commander of the army imprisoned. After a conflict emerged between Emperor Charles IV and Rudolf IV, Duke of Austria, rumors spread about a conspiracy to dethrone the emperor in favor of Louis or Rudolf. Charles IV, Rudolf IV and Louis met in Nagyszombat (now Trnava in Slovakia) in May. The emperor and the duke mutually surrendered their claims to the other party's realms. Louis also persuaded the emperor to renounce his suzerainty over the Duchy of Płock in Poland.