The Ambiani were a Belgic people of Celtic language, who were said to be able to muster 10,000 armed men, in 57 BC, the year of Julius Caesar's Belgic campaign. They submitted to Caesar. Their country lay in the valley of the Samara (modern Somme); and their chief town Samarobriva, afterwards called Ambiani and Civitas Ambianensium, is supposed to be represented by Amiens. They were among the people who took part in the great insurrection against the Romans, which is described in the seventh book of Caesar's Gallic War.
The Ambiani were consummate minters and Ambianic coinage has been found throughout the territories of the Belgic tribes, including the Belgae of Britain. There is some evidence from coins that bear a stag on one side and a betorced head on the obverse that the Ambiani were followers of the god Cernunnos (horned God). A few Ambiani coins have been found along the south coast of the West Country possibly as the result of trade across the English channel .