After losing the first battle of Decumantes last year, the Gauls retreated to Roman Parma while their ally Germany retreated to his heartland. The victorious Ponts moved most of their army to Athens fearful of a strike at their southern front leaving the Macedonians to continue the siege supported by just one Pontic division.
This year the Gauls took a punt that the Ponts would have moved troops south and again attacked Decumantes. This time supported by two Roman divisions. The Germans also attacked again, but were unable to coordinate their attack with their allies.