Battle of Hastings

William claimed that Edward the Confessor had promised him the throne and that Harold had sworn to support his claim. After almost nine months of preparation he gathered a fleet and an army from Normandy, Brittany, Flanders and other parts of France, crossed the Channel a few days after Harold's victory at Stamford Bridge and landed at Pevensey on 28 September 1066. Harold hurried south and on 14 October drew up his housecarls and the fyrd in a shield wall on Senlac Hill. The size of the armies is unknown: modern estimates range from about 5,000 to 13,000 men for the English and from 7,000 to 12,000 for the Normans, while the chroniclers' figures are wildly exaggerated. The English fought on foot with few archers; William had archers, infantry and cavalry.

The Norman archers and foot soldiers made little impression on the shield wall. When the Bretons on the left gave way and a rumour spread that William had been killed, the duke showed his face to rally his men, who turned on the English pursuers and cut them down. According to William of Poitiers, the Normans twice pretended to flee to draw more of the English down the slope. Harold fell late in the day, and his brothers Gyrth and Leofwine were also killed; how he died is uncertain — the story of an arrow in the eye is first recorded in the 1080s by Amatus of Montecassino, and the scene in the Bayeux Tapestry can be read in more than one way. Leaderless, the English broke, although Harold's household troops fought on around his body.

Some English leaders proclaimed Edgar Ætheling king, but after William's march around London they submitted at Berkhamsted, and Archbishop Ealdred crowned William in Westminster Abbey on 25 December 1066. Revolts went on for several years and were crushed, most brutally in the Harrying of the North in the winter of 1069–1070. Battle Abbey was founded on the battlefield — in fulfilment of William's vow according to 12th-century sources, more probably at the demand of papal legates in 1070 — with its high altar said to mark the spot where Harold died. Some English veterans of the battle left England and joined the Varangian Guard in Constantinople.