Battle of Morbihan Gulf

The Battle of Morbihan Gulf was a naval battle fought between Julius Caesar and the Veneti during the Gallic Wars (58-51 BCE).

56 BCE Thought to be Quiberon Bay, outside Morbihan Gulf, Brittany, France. The location is assumed, as it is not specified in the sources.

The Veneti were almost undefeatable on land as their strongholds were fortified peninsulars, protected by the sea.
In 57 BCE, P. Crassus was sent with an Army to obtain the submission of the Gallic Tribes of Northwestern France. The Veneti and others submitted at first, and P. Crassus retired to winter quarters. He then sent ambassadors to each of the tribes, requesting they send supplies. The Ambassadors were imprisoned by the Veneti and the other Tribes did the same.
Julius Caesar who was in Rome, ordered P. Crassus to build a fleet of Galleys in the Loire. Caesar then rejoined his armies in Gaul, and moved against the Veneti, capturing several towns. However, when the Romans besieged and entered their strongholds, the Veneti evacuated them by sea, leaving an empty fortress and retaining the advantage.

The Galleys of the Roman Republic under Julius Caesar
The Fleet of the Veneti:
- They were the Seapower in Gaul, who traded with Britannia from southern Brittany, based in well-defended peninsular fortresses surrounded by the sea. Their Capital was Darioritum (Vannes) on the Morbihan Gulf.

c. 100 Roman oared Galleys
- Under the command of Decimus Brutus.
- The Roman Galley Fleet was manned by skilled oarsman who were trained in galley tactics.
- Extra marines were deployed on the Galleys, with the intention of Boarding and overwhelming the Veneti ships.

c. 220 sailing warships.
- The Veneti had a fleet of high sided sailing ships built of oak with sails of leather, and high prows and sterns that could cut through the Atlantic rollers. The keels were flat, and they could negotiate shallow waters more easily than Roman galleys.
- The ships were higher, faster, and much more manoeuvrable under sail than the Roman Galleys, making it impossible to board them. They were also very difficult to ram, the usual galley tactics, due to the thickness of their wooden sides. Their high sides protected them from Roman missiles, whilst they could rake the lower Roman decks with their missiles.

The Roman Fleet left the Loire, under the command of Decimus Brutus, and moved up the coast to challenge the Veneti fleet near its harbour.
The Veneti fleet emerged from its stronghold (possibly Vannes in Morbihan Gulf) to engage the Roman Fleet, probably in Quiberon Bay, outside the Morbihan Gulf.

The Sea Battle lasted from ten in the morning until nightfall.
Julius Caesar and the Roman Army sat down on the shore of the Bay to watch the Battle.
Initially the advantage was with the Veneti fleet, the Romans were unable to attack them by ramming tactics, neither could they disable their higher sided vessels with their missiles. As the Veneti ships passed the Roman galleys, their much higher decks meant they could rake the lower Roman decks with missiles from above. Also, their sails gave the Veneti ships greater speed and they could easily outmanoeuvre the Roman galleys and avoid being boarded.
A stalemate ensued.
Finally, the wind collapsed and the Battle turned in favour of the Romans.
At this point, the Romans started using hooks on the end of long poles, to disable the leather sails of the Veneti ships. Once the ship was helpless, the Roman Marines boarded and captured the vessel. One by one the Veneti ships succumbed, until the surviving ships were forced to sail away from the battle.

It was the First major Roman Sea Battle in the North Atlantic using Roman Galleys.
After the Veneti had lost their fleet, their strongholds could no longer be evacuated by sea, and their strongholds were all forced to surrender one by one to Julius Caesar.
To make an example of the Veneti to the other Gallic Tribes, Julius Caesar executed all the Veneti Senators, and sold the entire Veneti Tribe into slavery.

Quiberon Bay, Brittany