The 100 years war??
The 100 years war is exactly the way it sounds: there was a war that was 100 years, and it was all on who wanted to be king of France.
Confused? Well this is what happened.
Imagine you are a noble in France and the king of France just died with no sons to take the throne, and two people plan to take it: one is French and the other is the King of England. Now when the French won the English(England) were mad because they wanted to take over France. So they did something about it and that's what started the 100 years war.
Joan of Arc
Now 99 years has past and Joan of Arc is winning battles as usual. Wait let me back up the story. Joan of Arc was a Christian knight in the 100 year war. She heard from God that he would help her with the battles. Now when France and England heard about this they were scared of her because she was a great knight, and she was only 15! She was French, so the English did something about it: they found her and killed her just because of her religion! The good part was after she died France won the war.
Effects of the war
After the war both England and France's governments change. For example in France the kings power increased because the won the war and the kings and knights finally got along. In England it was the opposite the kings power decreased and the Parliaments power increased because it was a costly war. The Parliaments are nobles that advise the king.