Normandy campaigns of 1200–1204

Normandy Campaigns
Phillip II's successful invasion of Normandy in 1204
Date 1202-1204 Location Normandy Result England loses Normandy, Anjou, and Maine to France, but retains Aquitaine
Belligerents
Kingdom of France Duchy of Brittany House of Lusignan	Kingdom of England
Commanders and leaders
Philip II of France Arthur of Brittany Hugh de Lusignan	John, King of England William Marshal William des Roches
Strength
French Army under Philip II Breton army under Arthur	Mercenary Army
Casualties and losses
unknown	unknown

The Normandy Campaigns were wars in Normandy from 1202 to 1204. The Kingdom of England fought the Kingdom of France as well as fighting off rebellions from nobles. King Philip II of France conquered the Anglo-Angevin territories in Normandy, resulting in the Siege of Château Gaillard. The Normandy Campaigns ended in a victory for France when the Anglo-Angevin territory was greatly diminished.

After King Richard the Lionheart's death on 6 April 1199 there were two potential claimants to the Angevin throne: John, whose claim rested on being the sole surviving son of Henry II, and young Arthur of Brittany, who held a claim as the son of Geoffrey. Medieval law gave little guidance as to how the competing claims should be decided, with Norman law favouring John and Angevin law favouring Arthur; the matter rapidly became an open conflict. John was supported by the bulk of the English and Norman nobility and was crowned king at Westminster, backed by his mother, Eleanor. Arthur was supported by the majority of the Breton, Maine and Anjou nobles and received the support of Philip II, who remained committed to breaking up the Angevin territories on the continent. With Arthur's army pressing up the Loire valley towards Angers and Philip's forces moving down the valley toward Tours, John's continental empire was in danger of being cut in two.

Warfare in Normandy at the time was shaped by the defensive potential of castles and the increasing costs of conducting campaigns. The Norman frontiers had limited natural defences but were heavily reinforced with castles, such as Château Gaillard, at strategic points, built and maintained at considerable expense. It was difficult for a commander to advance far into fresh territory without having secured his lines of communication by capturing these fortifications, which slowed the progress of any attack. Armies of the period could be formed from either feudal or mercenary forces. Feudal levies could only be raised for a fixed length of time and proved an inflexible asset; mercenary forces, often called Brabançons after the Duchy of Brabant but actually recruited from across northern Europe, could provide much greater military agility and operate all year long, but cost much more than equivalent feudal forces.

...
Wikipedia