First Battle of Porto
1809 CE.
Shown on the map at 41.149°, -8.611°.
In the First Battle of Porto (29 March 1809) the French under Marshal Soult defeated the Portuguese, under General Parreiras, outside the city of Porto during the Peninsular War. Soult followed up his success by storming the city, in the course of which thousands of fleeing citizens drowned in the Porto Boat Bridge disaster.
Text from the Wikipedia article First Battle of Porto, licensed CC BY-SA 4.0.