Iron does not make history however.  Written words do.  The Gauls did not write, but the Greeks and Romans who knew them did.  While physical evidence gives us no trace of it, the texts of Greek and Romans tell us that these strange people washed their heads with special preparations that made their hair especially fluffy!  The men did not wear togas but rather a strange garment that covered both legs and wrapped around the waste and groin, and another that wrapped the arms and upper body.  The French words "chemise" and "braie" -- shirt and britches -- both come from the language of the Gauls.  Their language and costume thus both leave a direct trace in our modern memory.