In a now province of The Netherlands, Frysian, there was once a man that wanted everybody to know how to say "buter, brea en griene tsiis wa dat net sizze ken is gjin oprjochte frysk" People who could not say this in the correct language were dead but the people who could were free to go. So this Invasion is about you not giving your stuff to him and defending yourself from him. Goodluck.
Long time ago there was in Frysian a man that sailed through the Northern seas close to the Netherlands. He entered ships and stole a lot. If the people on the ship wanted to life they had to say a Frysian sentence:
"Buter brea en Griene tsiis wa dat net sizze ken is gjin oprjochte Frysk"
Offcourse few people could say this, So this man also was a big man at the land and asked for people's food and drink.
Once there was a country that decided to say not to give the stuff. So Lytse pier got very angry and decided to Attack the first castle.
It is to you to defend the castle from lytse Pier.
The king is in a good mood and you should first make weapons before training an army perhaps the king thinks you are a good lord and sends you some archers to defend yourself IF you know how to quickly make weapons.