It is the year 1450 AD. Kampen - formerly one of Europe's biggest trading hubs and candidate for the capital of the Netherlands - is part of the Hanseatic League. The city is bordering the Zuiderzee (South Sea), making it easy to reach Amsterdam and London on the one hand, and the river IJssel running into Germany on the other. The Hanseatic League is a trade cartel consisting of cities in Eastern Netherlands, Germany, Poland and the Baltic States that agreed to collaborate to suppress and exclude other cities that threatened their wealth. They do this by monopolising trade on some of the most profitable goods (e.g., grain, wood, skin, wine and spices), exclusive storage rights in harbours and limiting expertise in how to build ships to cities within the Hanseatic League.
Recently, the Hanseatic League has been facing competition from Western European cities in Denmark, Flanders (Belgium), Scotland, England and Western Netherlands (including Amsterdam, another candidate capital of the Netherlands). Some cities in Poland from the Hanseatic League have broken the agreements and now allow trading, mostly with Amsterdam as Amsterdam offers significantly cheaper prices. Following its declining dominance, the Hanseatic League has become more aggressive and blocked access to the East Sea for all cities not part of the League. Ships from Amsterdam have just broken this blockade and the city demands that - rather than neutrality - Kampen drops from the league and stops trading with their respective cities.
This is not relevant for the debate, but Martijn felt like you should know.