William of Poitiers is the sole contemporary authority on the claim that Pope Alexander II sponsored William the Conqueror's invasion of England in 1066. Poitiers’ references to the banner are best described as laconic, referring to it three times in the Gesta Guillelmi. The banner was first recorded in a single sentence in which Poitiers related how an embassy was sent to Rome. It then reappears at Hastings, where Poitiers described how the Normans formed up ‘behind the banner which the pope had sent’. Finally, it was alluded to when Poitiers recounted how booty and Harold's standard were sent to Rome as ‘an equal return to the pope for the gift sent to him through the pope's generosity’.

This article will re-examine Poitiers’ claim that the papacy sponsored the Conquest. The current consensus has been to accept Poitiers’ testimony, with H.E.J. Cowdrey, David Bates, and Elisabeth van Houts going as far as to affix their own standards to the mast, with all three arguing that there is no doubt as to the banner's existence. This uncritical acceptance of Poitiers’ claim does not satisfy the current approach to the evidence on the Conquest. The work of George Garnett and Tom Licence has encouraged a far more rigorous appraisal of the sources for 1066, arguing that we ought to read the Norman claims to the throne as essentially fabricated in the aftermath of the invasion. It is this approach that will be applied here, arguing that the current consensus is unwarranted, and that it was highly unlikely that Alexander granted William a banner in 1066 to sanction his invasion.

In doing so, this article will seek to build upon the lone detailed critique on the papal sponsorship, which was provided by Catherine Morton. Three arguments were at the heart of Morton's case against the banner: first, the improbability that Alexander would have sanctioned William's invasion; second, our reliance on Poitiers’ sole testimony; and third, that the Penitential Ordinance undermines the likelihood of papal sponsorship.