By the 340s, he had united under his power Scythian tribes inhabiting a vast territory between the Danube and the Maeotian marshes.
Towards the end of his life, Ateas increasingly encroached upon the Greek-Macedonian sphere of influence in the Balkans.
When Philip's troops arrived to Scythia, they were dismissed with derision: the king of the Histriani had died and military action was no longer on the agenda.
Another collision between Philip and Ateas arose during the former's siege of Byzantium, when the Scythians refused to provide Macedonian troops with supplies, citing the barrenness of their land as a pretext.
The final straw was the Scythians' reluctance to allow Philip to dedicate a statue of Heracles at the Danube estuary.