Which pope granted William a papal banner for the invasion?

The pope who granted William a papal banner for the invasion of England was Pope Alexander II. In 1066, William sent an embassy to Rome seeking papal approval for his planned campaign against Anglo-Saxon England, and Alexander granted his blessing.

According to accounts of the expedition, the pope sent William a ring and a banner, or gonfalon, bearing a cross. The banner was a powerful symbol: it suggested that William's campaign had papal support and could be presented as a legitimate effort to reform or bring the English Church into closer alignment with Rome.

The Bayeux Tapestry depicts William with a papal gonfalon, while Count Eustace of Boulogne is shown carrying the papal insignia. The exact ceremonial details are filtered through Norman sources, but Alexander's support and the banner are firmly associated with the invasion narrative.

After Hastings, Alexander's backing helped William secure the submission of the English clergy. The pope later sent legates to England, and William restored the payment known as Peter's Pence, strengthening Rome's influence over the English Church.