Petrocorii.
 

Petrocorii is a celtic tribe living in Aquitain region with Vesonna (Perigueux). Petrocorii in gallic means four armies. They fought against Caesar in the Gaulish coalition. They are known as good metal workers and iron forging.
 

 Silver Drachma of Petrocorii.  c. 121 - 52 BCE.
Obverse: Heard facinf left.
Reverse: Cross
Weight: ~3.4 grams. Size: ~12 mm.
Reference: S 160;  LT 3331