That Time When a City and a Bishop Went to War Over Beer

Beer was a big part of life in Europe in 1380. In the city of Wrocław, which is now in Poland, beer was so important that it sparked a war. Building and maintaining a brewery was quite expensive, and the only entities that could afford to do it were the government and the church. Wrocław had its municipal brewery, right underneath the Town Hall. The city government, called the Rata, sold beer and taxed it, too. But the monks on the nearby island of Ostrów Tumski made beer as well, and it was a better quality brew. The Rata didn't have control over the island or its monasteries, but they didn't want to cede their beer profits. 

The Rata tried diplomacy first. The council sent representatives to the island to explain their disappointment, but also, Van Reed writes, threatened confiscations and sanctions if things did not change.
The Bishop responded to the provocation with a bunker-buster: He placed the entire city under interdict, which meant that no religious service could be conducted within it. Basically, he cut Wrocław off from God so he could keep selling beer.

Wrocław's Rata responded by calling up an army. However, that army was made up of citizens who already preferred the monastic beer, and continued to drink during the war. Read about the Wrocław Beer War at Atlas Obscura.