This coin depicts the head of a bearded man, his hair spiked with lime. It is generally taken to be Vercingetorix, chief opponent of the Roman general Julius Caesar in his campaigns in Gaul (roughly modern France).
A captive in Rome at the time this coin was made, he was later publicly strangled for his part in the rebellion. The reverse shows a charioteer holding a shield and spear, driving two horses. This is perhaps a reference to the skill of the Gauls in chariot warfare.