Siege of Tartu
1224 CE.
Shown on the map at 58.380°, 26.723°.
The siege of Tartu, or Dorpat, took place in 1224 and resulted in the fall of the last major center of Estonian resistance in the mainland provinces to the Christian conquest of Estonia.
Text from the Wikipedia article Siege of Tartu (1224), licensed CC BY-SA 4.0.