 A third army, smaller still, under the command of Patriarch Poppo of Aquileia went through the Apennines to join Henry II in besieging the Byzantine fortress of Troia.Though Patriarch Pilgrim captured Pandulf IV of Capua and extracted oaths of allegiance from both Capua and the Principality of Salerno, all three of Henry II's armies failed to take Troia.The Byzantine troops could not be forced into a pitched battle, and Henry II was forced to turn back, his army weakened by diseases and suffering heavy losses.