Bari, Trani and Andria. They had already found themselves a powerful ally in Manuel, the Byzantine Emperor, and welcomed anyone—including Adrian—who was hostile to William. Their leader, Count Robert of Loritello, had been charged with treason by William but had managed to escape north. William was temporarily struck down with an unknown illness, as the scholar Joshua C. Birk explains, "this brought the enemies of the kingdom of Sicily out of the woodwork"; among them, Adrian excommunicated William. By 1154, William had captured important towns in the Patrimony. In summer 1155 rebellion broke out in southern Italy by the native nobility against their lord, the King of Sicily. One group of rebels, having gained the support of Emperor Manuel, overran Ancona. By winter 1155, suggests Norwich, few contemporaries "would have held out much hope for the future of the Sicilian monarchy". According to Boso, the rebels asked Adrian to come to them as their feudal lord, to act as their spiritual advisor and bless them in their endeavours. Adrian, believing that William's kingdom would collapse imminently, tried to exploit William's weakness and allied with the rebels in September. As it turned out, this was a miscalculation. William had already asked Adrian for a peace conference, which the Pope had ("scornfully") rejected. Alliance with Manuel I, 1156 Emperor Manuel I had launched his own military operation against William in southern Italy in 1154. He found Adrian a willing ally. The Russian historian Alexander Vasiliev notes that Adrian "expressed his desire 'to help in bringing all the brethren into one church' and compared the eastern church with lost drachma, wandering sheep, and the dead Lazarus". Adrian's isolation led directly to his concordat with the Eastern Empire in 1156, although Duggan emphasises that he was reacting to external political pressures rather than deliberately initiating a new policy. As a result, says Barber, he "became involved in a fruitless Byzantine plan to overcome the Normans which ended, as so often before when the popes had ventured south in arms, in Norman victory". Adrian—as if, says Partner, "the unhappy experiences of at least three popes ha taught the papacy nothing"—organised a papal army comprising Roman and Campagnan nobility and crossed the border into Apulia in September 1155. Although it has been suggested that Manuel offered to pay Adrian a large sum of money in return for ceding him certain Apulian cities, it seems unlikely that