When they arrived in the enemy’s country, three days were spent in fortifying the temple and throwing up entrenchments. This point was of great strategic value. If the Athenians could keep it, they would have a fortress on the frontier of Boiotia, inside their neighbours’ territory, whence so many invasions had of late years come upon them. Hippokrates, having finished his entrenchments, and having placed there a small force of foot and horse for the defence of the newly-acquired fortress, ordered the main body to return to Attika. The light-armed went first, and had got safely across the frontier before the heavy-armed and the cavalry had left the temple. Hippokrates stayed behind, for a time, at Delion. The hoplites and the cavalry, after a rapid march, halted on the frontier, about a mile from Oropos. They were about to start again, after a short rest, when, late in the afternoon, a herald from Hippokrates galloped up in haste with orders to range themselves at once in line of battle, for the forces of Boiotia and her allies, twenty thousand men, fresh and eager for the fight, were coming over the hills to fall upon them. Hippokrates, who soon came up, had not eight thousand men, all told, to meet this unexpected blow, and they were tired out with marching. The general got them into some sort of order, and was addressing them, pointing out the immense importance of gaining a foothold in Boiotia, to stop the incursions the Spartans, with the help of the Theban cavalry, were able continually to make upon the soil of Attika, when he was interrupted by the war-cry of Boiotia, and the Boiotians and their confederate forces were upon them. The Athenians rushed to meet them. They were only eight men deep; the Thebans were twenty-five. The shock was terrible. The Athenian right wing, throwing itself on the Boiotian left, where the Thespians fought, drove it back, and cut the Thespians to pieces. But they went too far, and got involved with the deep columns of the enemy, and lost as many as they slew. On their left wing the Athenians were broken at the onset, and retreated, overpowered by numbers. The centre and so much of the right wing as could disengage themselves followed in good order. But as they turned the hillside they saw the Boiotian cavalry, fifteen hundred strong, charging down upon them. They broke and fled in all directions. Some made their way back to Delion, others to the sea at Oropos; others, struggling through the passes of Parnes, at last got home again to Athens. The enemy, pursuing them, did fearful execution in their ranks.