Siege of Massilia
48 BCE.
Shown on the map at 43.297°, 5.376°.
The siege of Massilia, including two naval engagements, was an episode of Caesar's Civil War, fought in 49 BC between forces loyal to the Optimates and a detachment of Caesar's army. The siege was conducted by Gaius Trebonius, one of Caesar's senior legates, while the naval operations were in the capable hands of Decimus Brutus, Caesar's naval expert.
Text from the Wikipedia article Siege of Massilia, licensed CC BY-SA 4.0.