Baldwin could have no children and could not be expected to rule much longer. After the death of William of Montferrat in 1177, King Baldwin's widowed sister Sibylla required a new husband. At Easter in 1180, the two factions were divided even further when Raymond and his cousin Bohemond III of Antioch attempted to force Sibylla to marry Baldwin of Ibelin. Raymond and Bohemond were King Baldwin's nearest male relatives in the paternal line, and could have claimed the throne if the king died without an heir or a suitable replacement. Before Raymond and Bohemond arrived, however, Agnes and King Baldwin arranged for Sibylla to be married to a Poitevin newcomer, Guy of Lusignan, whose older brother Aimery of Lusignan was already an established figure at court. The dispute affected William, since he had been appointed chancellor by Raymond and may have fallen out of favour after Raymond was removed from the regency. When Patriarch Amalric died on 6 October 1180, the two most obvious choices for his successor were William and Heraclius of Caesarea. They were fairly evenly matched in background and education, but politically they were allied with opposite parties, as Heraclius was one of Agnes of Courtenay's supporters. It seems that the canons of the Holy Sepulchre were unable to decide, and asked the king for advice; due to Agnes' influence, Heraclius was elected. There were rumours that Agnes and Heraclius were lovers, but this information comes from the partisan 13th-century continuations of the Historia, and there is no other evidence to substantiate such a claim. William himself says almost nothing about the election and Heraclius' character or his subsequent patriarchate, probably reflecting his disappointment at the outcome. Death William remained archbishop of Tyre and chancellor of the kingdom, but the details of his life at this time are obscure. The 13th-century continuators claim that Heraclius excommunicated William in 1183, but it is unknown why Heraclius would have done this. They also claim that William went to Rome to appeal to the Pope, where Heraclius had him poisoned. According to Peter Edbury and John Rowe, the obscurity of William's life during these years shows that he did not play a large political role, but concentrated on ecclesiastical affairs and the writing of his history. The story of his excommunication, and the unlikely detail that he was poisoned, were probably an invention of the Old French continuators. William