Such was the state of things in the Peloponnese when King Philip, after crossing Thessaly, arrived in Epirus. Reinforcing his Macedonians by a full levy of Epirotes, and being joined by three hundred slingers from Achaia, and the five hundred Cretans sent him by the Polyrrhenians, he continued his march through Epirus and arrived in the territory of the Ambracians. Now, if he had continued his march without interruption, and thrown himself into the interior of Aetolia, by the sudden and unlooked-for attack of so formidable an army he would have put an end to the whole campaign: but as it was, he was over-persuaded by the Epirotes to take Ambracus first; and so gave the Aetolians an interval in which to make a stand, to take precautionary measures, and to prepare for the future. For the Epirotes, thinking more of their own advantage than of that of the confederacy, and being very anxious to get Ambracus into their power, begged Philip to invest the town and take it before doing anything else: the fact being that they regarded it as a matter of the utmost importance to recover Ambracia from the Aetolians; and thought that the only way of doing this was to become masters of this place, Ambracus, and besiege the town of Ambracia from it. For Ambracus is a place strongly fortified by walls and out-works, standing in the midst of marshes, and approached from the land by only one narrow raised causeway; and commanding by its situation both the district and town of Ambracia.