Battle of Turin
312 CE.
Shown on the map at 45.067°, 7.700°.
The Battle of Turin was fought in 312 between Roman emperor Constantine the Great and the troops of his rival Maxentius. Constantine won the battle, showing an early example of the tactical skill which was to characterise his later military career. The campaign ended with his more famous victory at the Milvian Bridge immediately outside of Rome.
Text from the Wikipedia article Battle of Turin (312), licensed CC BY-SA 4.0.