Battle of Allenstein
1807 CE.
Shown on the map at 53.863°, 20.397°.
The Battle of Allenstein (or Olsztyn), also known as the Battle of Jonkowo (or Jankowo, Inkowo, Jonkendorf) and the Battle of Bergfriede, was a military engagement during the early stages of the 1807 Fourth Coalition Napoleonic campaign. While the battle resulted in a French field victory and allowed for a successful pursuit of the Russian army, it failed to produce the decisive engagement that Napoleon was seeking.
Text from the Wikipedia article Battle of Allenstein, licensed CC BY-SA 4.0.