The hostility between two royal houses stretched across a vast historical span—from the era of the early Crusades and the flourishing of courtly culture to the decline of classical Middle Ages (12th–15th centuries).
In the history of this struggle there was everything: passionate love and jealousy, family squabbles and intricate intrigues, battles on a grand scale for their time as well as peaceful treaties that, as always, carried the threat of a new war. In the coat of arms of the rulers of France there are lilies; of the English kings—leopards.
The starting point for the curious interweaving of the historical fates of France and England was an event of the mid-11th century: the conquest of the Anglo-Saxon kingdom by the North French feudal lord, the Duke of Normandy, William the Conqueror. The Kingdom of France began to take shape as a relatively separate state by the end of the 10th century. Within it, there was still no political and territorial unity, although the king of the first French Capetian dynasty already stood at the head. The largest feudal lords—dukes and counts—behaved toward the early Capetians with considerable independence. The very concept of a state border was absent, and the right of the stronger often decided the most serious political questions.
It was on this that the bold, in essence adventurous enterprise of William the Duke of Normandy was founded: in 1066 he landed on the southern English coast with a comparatively small army and achieved an astonishingly easy victory over the militia of scattered—and more backward—Anglo-Saxon kingdoms. William the Conqueror became King of England while naturally keeping his power over the Duchy of Normandy in Northern France.
This event set in motion attempts spanning several centuries by the Norman dynasty of English kings and their successors to create and maintain a political entity extending over the British Isles and the territory of France.