Why did the French and English have so many conflicts during the High Middle Age

Question:how did it lead to the hundred year war?

Best Answer - Chosen by Asker: how did it lead to the hundred year war?

William the conqueror was both the king of England and the duke of Normandy, and a very powerful duke at that. This finally became way too dangerous for the king of France who did his best to break William's power in Normandy. That was the start of the constant warring between England and France. His sons kept the tradition, the Duke of Normandy (first son) and the king of England (second son) warred incessantly. Normandy stayed a vassal to the French king. The English were not pleased.
An English king Edward II married a French princess Isabelle de France who was the only heiress in direct descent to the throne, and claimed the French crown through her for his son. The French answered by creating a law that made it impossible for women to inherit titles. The English were not pleased.
Tit for tat, Eleanor of Aquitaine, after marrying and divorcing the French King Louis VII went on to marry Henry II of England and brought with her a huge chunk of the French kingdom (1/5 of it) which the English king gleefully called English land. The French were not pleased.

It's a very long history, starting way before the Middle Ages.
In fact, England and France have always been at each other's throats at one point or another, for reasons that were very simple: how do we increase our power?
In fact, the current period of peace is the longest that has ever occurred between the two countries.
The European Community is trying to ensure that there is no more war on the continent, but that is another story.

It started when the king of the Franks ( French ) gave the king of the Normans ( vikings ) the northern 1/4 of France if he would just stop raiding that area and convert to Christianity and accept the king of the french as his king . Later the Normans conquered England and basically became the English . The English ruled Normandy as there's ignoring the french king . France decided they wanted Normandy back . Thus the 100 years war . France did eventually win Normandy back from England but it created a rivalry that would last for centuries .

At its heart, a family feud over the inheritance of land that had nearly a millenia's worth of soap opera twists and turns.

Research Henry II of England who was also Count of Anjou in France. Then he ups and marries Eleanor of Aquitaine who is heiress to really large estates in southeastern (?) France. Eleanor had just divorced Louis VII of France.

Henry II thought he should not owe obeisance to Louis, because he was king in his own right. Simply put, he claimed that his and his wife's French territories belonged to England, not France. Thus began a long feud.