1415:

The Battle of Agincourt

This famous battle, immortalized by Shakespeare, was a decisive victory by King Henry V of England and his forces over the French in the Hundred Years' War.

1154:

King Stephen of Blois

After the death of King Henry I, Stephen stepped in to take the throne, preventing Henry's daughter Matilda from ruling, and setting off a civil war.

1400:

Geoffrey Chaucer