Gregory’s time in the Holy Land did not simply give him an attachment to the place, which would lead him to launch a new crusade to reclaim it for the Christians. It also enabled him to see the manner in which the remaining crusader territories were being run. He could not have been pleased with what he saw, and this very likely contributed to the interim troops being placed under western captains, rather than under the permanent secular leaders of the East. That there were problems was indisputable. The Latin kingdom was chronically losing territory to the powerful Mamluk sultan, Baybars. Apportioning the blame for this troubled time, however, is more difficult. Criticism of the state of the Latin kingdom and the way in which it was run in the thirteenth century is widespread, and has been discussed by several historians.

It has been alleged that, due to the poor government in the Latin East, Pope Gregory X colluded with Charles of Anjou to unseat Hugh of Lusignan, de facto king of Jerusalem, to place Charles on the throne by buying Maria of Antioch’s claim. Charles did not buy Maria’s claim until 1277, after Gregory had died. Nevertheless, this has not prevented historians from placing Gregory right in the very heart of the matter, with this notion being sustained, quite incredibly, with no solid evidence. Steven Runciman did much to give birth to this erroneous idea: ‘Gregory while he was in the East may have shown the disappointed princess some sympathy, so that she felt it worthwhile to come to the council of Lyons.’ In fact, Maria had left the Holy Land before Gregory had even arrived there. Runciman also recounted that Maria ‘continued to enjoy the pope’s favour, and he suggested that, as she was unlikely to establish herself at Acre, she should sell her rights to Charles of Anjou.’ Picking up on Runciman’s theory, Sylvia Schein argued that it was Gregory who ‘encouraged Maria to sell her claims to Charles I of Anjou as he wished him to take a more active interest in the fate of the crusader state, not only for its own welfare but also to divert Charles from his ambitions in Byzantium.