Lost Papal Letter Recasts 1066 as Holy War Against Satan’s Followers

The Norman Conquest of England in 1066 may have been driven by more than a disputed royal succession, according to new research from the University of East Anglia. Previously overlooked excerpts from a lost papal letter suggest that political divisions within the medieval Church helped shape Pope Alexander II’s decision to support William of Normandy’s invasion. The evidence points to a conflict that extended from England to Rome and involved rival claims to papal authority, competing European power blocs and the religious justification of military action.

The findings, presented by UEA medieval historian Professor Tom Licence in his new book Harold: Warrior King, challenge the traditional explanation of papal support for William. Historians have generally argued that Alexander backed the Norman duke because Harold Godwinson had allegedly broken an oath to William and occupied a throne to which he had no legitimate claim. Licence’s interpretation suggests that Harold’s relationship with the papacy may have been equally important, and that England’s political alignment in Rome could have helped transform the invasion into what supporters of William regarded as a just or holy war.

The key evidence comes from two excerpts preserved in medieval collections of papal rescripts held in the Vatican archives. Pope Alexander II’s complete register of correspondence has been lost, but parts of individual letters survived because later scholars and church officials copied or quoted them in canon-law compilations. These fragments are technically significant because they preserve the language through which the papacy described England’s political and religious position after William’s accession. Rather than offering a neutral account of the conquest, the text presents England as a territory that had abandoned the protection and authority of St Peter.

In one passage, Alexander claimed that the English had been protected by St Peter until people “fired with the pride of their father Satan” led them away from “the path of truth.” Such language was not simply a condemnation of Harold’s alleged oath-breaking. Licence argues that it reflects the polemical vocabulary used during a major papal schism in the early 1060s, when Western Christendom was divided between Alexander II and Cadalus, Bishop of Parma, who adopted the papal name Honorius II. The reference to Satan may therefore have been aimed at political and religious opponents associated with the rival papal faction.

The schism began in 1061, when competing groups elected Alexander and Cadalus. Their dispute was not merely theological. Each claimed to be the legitimate successor of St Peter, and both sought recognition from rulers, bishops and military supporters across Europe. Honorius received backing from the Holy Roman Empire and attracted allies in northern Europe, while Alexander fought to consolidate his authority in Rome. In this environment, a kingdom’s support for one papal claimant could carry consequences far beyond ecclesiastical ceremony. Allegiance to a pope could influence diplomatic relationships, royal legitimacy and the willingness of other rulers to recognize a government.

According to Licence, England may have supported Alexander’s opponents during this period or adopted a position that was interpreted in Rome as hostile to Alexander’s cause. The precise nature of Harold’s involvement remains uncertain, because the surviving sources are fragmentary and often written by political winners. However, if the English court was associated with the rival faction, Alexander could have viewed the fall of Harold as part of a broader struggle to defeat his enemies. Under this interpretation, William’s invasion offered the pope an opportunity to weaken a hostile political alignment while installing a ruler more likely to support papal interests.

This possibility helps explain why a pope would lend religious authority to the violent overthrow of an anointed king. Papal approval did not necessarily provide William with a modern legal mandate, but it could frame the invasion within the medieval concepts of justice, obedience and legitimate rule. A papal banner or endorsement could reassure Norman supporters that their campaign served a higher religious purpose. It could also portray Harold not only as a rival claimant but as a ruler aligned with forces condemned by Alexander’s supporters as enemies of the true Church.

The interpretation does not remove the dynastic causes of the Norman Conquest. Edward the Confessor’s death, Harold’s accession, William’s claim based on alleged promises and the disputed oath at Bayeux remained central to the crisis. Nor does the evidence prove that the papal schism alone determined the outcome. William still needed ships, soldiers, logistics and favorable conditions to cross the Channel, while Harold’s army was defeated at Hastings after a succession of exhausting campaigns. The new research instead adds a Roman dimension to the events, showing how ecclesiastical politics may have strengthened William’s legitimacy before the battle was fought.

The discovery is particularly important because medieval political language often concealed practical power struggles beneath religious symbolism. References to Satan, truth and the protection of St Peter could function as coded accusations of disloyalty within a divided institutional system. By comparing the Vatican excerpts with letters, canon-law materials and accounts of the papal schism, Licence has connected phrases previously treated as unexplained rhetoric to the conflict between Alexander and Honorius. The result is a picture of 1066 in which England’s fate was influenced not only by armies in Sussex but also by struggles over who possessed the authority to speak for the Christian Church.

The research appears as the British Museum prepares an exhibition featuring the Bayeux Tapestry, one of the most important surviving visual sources for the Norman Conquest. The tapestry depicts Harold’s journey, William’s preparations and the violence of Hastings, but it offers only limited insight into the international politics surrounding the invasion. The Vatican excerpts provide a rare glimpse of how the conquest could be represented from Rome. They suggest that William’s victory was not simply a successful bid for an English crown: to Alexander’s supporters, it may have formed part of a European campaign against a rival religious and political order.

References: Tom Licence, Harold: Warrior King, Yale University Press; excerpts from a lost letter of Pope Alexander II preserved in medieval canon-law collections in the Vatican archives.