Histories

Then when day came, he invited the Barcaeans to confer with him, and they readily consented; at last all agreed to conditions of peace. This was done thus: standing on the hidden trench, they gave and accepted a sworn assurance that their treaty would hold good while the ground where they stood was unchanged; the Barcaeans promised to pay a due sum to the king, and the Persians to do the Barcaeans no harm.

When the sworn agreement was made, the townsfolk, trusting in it and opening all their gates, themselves came out of the city, and let all their enemies who so desired enter within the walls. But the Persians broke down the hidden bridge and ran into the city. They broke down the bridge that they had made, so that they might keep the oath which they had sworn to the Barcaeans: namely, that this treaty would hold good for as long as the ground remained as it was; but if they broke the bridge the treaty held good no longer.