Battle of Jarosław
1939 CE.
Shown on the map at 50.017°, 22.667°.
The Battle of Jarosław (known as the Defence of Jarosław in Polish sources) took place between 10 and 11 September 1939 in the city of Jarosław on the San River. During the battle the Polish forces of General Stanisław Maczek successfully held the river crossings in the town for two days against the Nazi German Wehrmacht, which was enough time for the Polish 10th Motorized Cavalry Brigade to cross the river and retreat further eastwards.
Text from the Wikipedia article Battle of Jarosław, licensed CC BY-SA 4.0.