Battle of Uppsala
1520 CE.
Shown on the map at 59.858°, 17.645°.
The Battle of Uppsala also called the Battle of Good Friday was a bloody battle between the Danish mercenary army and a Swedish peasant army in Uppsala during the Dano-Swedish War (1512-1520). It was the bloodiest battle in the Dano-Swedish war, with casualties in the thousands.
Text from the Wikipedia article Battle of Uppsala, licensed CC BY-SA 4.0.