The Veneti inhabited southern Armorica, along the Morbihan bay. They built their strongholds on coastal eminences, which were islands when the tide was in, and peninsulas when the tide was out. Their most notable city, and probably their capital, was Darioritum (now known as Gwened in Breton or Vannes in French), mentioned in Ptolemy's Geography.
The Veneti built their ships of oak with large transoms fixed by iron nails of a thumb's thickness. They navigated and powered their ships through the use of leather sails. This made their ships strong, sturdy and structurally sound, capable of withstanding the harsh conditions of the Atlantic.
Judging by Caesar's Bello Gallico the Veneti evidently had close relations with Iron Age Britain; he describes how the Veneti sail to Britain. They controlled the tin trade from mining in Cornwall and Devon. Caesar mentioned that they summoned military assistance from that island during the war of 56 BCE.
Julius Caesar's victories in the Gallic Wars, completed by 51 BCE, extended Rome's territory to the English Channel and the Rhine. Caesar became the first Roman general to cross both bodies of water when he built a bridge across the Rhine and conducted the first invasion of Britain.