It is the year 1337, and a French messenger alerts the English king Edward III that he has to pledge allegiance to the French throne...
...Which sparks a 116 year-long war known as the Hundred Years' War.
We already have a king, and he wants you to pledge allegiance, or lose Aquitaine.
Over my dead body!
I don't need to pledge! I am French, too!
That can be arranged!
Now it is 1415, right before the Battle of Agincourt. A French messenger has come to offer terms with the English.
So, they went into battle. The English forced a much larger French army into a narrow area and beat them. 6,000 French were killed, and only 400 English were killed.
Will you take the deal? This is the only opportunity to take it.
Never! Longbowmen, shoot him!
It is 1429, and a seventeen year-old girl named Joan of Arc convinced the disinherited Charles VII that God had sent her to lead the French Army to defend Orleans against the English.
There was only a little bit of fighting, and the French kept Orleans under their control. Joan was captured and eventually burned, but her death motivated the French to win the war.
I am a messenger of God. He sent me here to tell you to retreat!
Really? Fine, we will retreat.
It is a few months before the Siege of Orleans. The old French king, Charles VI, who is claimed to be a little crazy, disinherits his own son and marries his daughter to the English king, Henry V.
Now desperate, Charles VII enlists the help of Joan of Arc to lead his army in the Siege of Orleans. In the next year, both Charles VI and Henry V die, leaving Charles VII king of France and Henry V's toddler son the king of England.
A few months later, the Hundred Years' War ends. Upon realizing that they could no longer claim land on the continent, the English go find somewhere else to rule, sparking the English Age of Exploration. Also, feudalism, the system that both countries have used during the Middle Ages, ends, and Nationalism, the idea that the people are untied under one king and country, arised. Because feudalism ended, both countries no longer needed knights.
The year is now 1453, and the French completely devastate the English with the use of cannons in a battle known as the Battle of Castillion.