Sweyn of Denmark invades the southern coast and kills William the Conqueror. In the vacuum of power, Anglo-Saxon exiles, Flemish nobility related to William, and the King of Scotland invade to try and restore order.
Olaf III or Magnus II of Norway invade England again for a Norwegian rematch. He takes over but then gets killed by Scottish assassin. Earl Edwin, who survived William's reign, takes over England.
The devastated England, suppression of the old English, and excess of new ruling lords that have to pay off their war debts, is extremely taxing to the peasantry, who join a heretical movement such as the Lollards (but earlier) en masse. A peasants' revolt begins, influenced by heresy as well.
The heretic revolt requires Papal intervention, so the King of France takes over England to bring it back to the Church.
The Holy Roman Emperor can't stand the increase in the power of France, so he invades France while sending a claimant to invade England. However, a revolt occurs in Frisia centered at Groningen, and the HRE dies in the North Sea while sailing back to Germany.
The HRE-supported claimant to England (probably a remaining Anglo-Saxon exile) takes over, but due to the belligerence between him and France, the King of France invades again using a new Breton-Norman force, and places a claimant from Brittany.
The Christianized Vikings of Dublin and the Hebrides/Western Isles raid the coasts of England.
Somehow get Matilda of Tuscany and the Southern Italy Normans involved.