Presently there came a message to Mardonius that the Greeks were gathered together on the Isthmus. Thereupon he marched back again through Decelea; the rulers of Boeotia sent for those of the Asopus country who lived nearby, and these guided him to Sphendalae and from there to Tanagra. Here he camped for the night, and on the next day he turned from there to Scolus, where he was in Theban territory. There he laid waste the lands of the Thebans, though they sided with the Persian part. This he did, not for any ill-will that he bore them, but because sheer necessity drove him to make a stronghold for his army and to have this for a refuge if the fortune of battle were other than he wished. His army, stationed along the Asopus river, covered the ground from Erythrae past Hysiae and up to the lands of Plataea. I do not mean to say that the walled camp which he made was of this size; each side of it was of a length of about ten furlongs.