At the end of winter in 200 BC, Sulpicius led his troops east through the territory of the Dassaretae. Philip gathered 20,000 infantry and 4,000 cavalry, recalling the troops he had stationed in the north with Perseus, and marched west. He encamped on a hill near Athacus which overlooked Sulpicius' camp. After a series of indecisive skirmishes (in one of which Philip was nearly captured), news came that the Dardanians had invaded northern Macedonia, and the Macedonians withdrew secretly in the night. When he realised what had happened, Sulpicius set out in pursuit through Pelagonia, found Philip blocking the pass to Eordaea and forced it. Sulpicius ravaged Eordaea, then Elimeia to the south, and then followed the Haliacmon river valley up to Orestis, where he conquered Celetrum and Pelion and then returned to his base. Philip split his force, sending a contingent of his army north to deal with the Dardanian invasion, which it did, while he himself headed south.