Xenophon relates that the inhabitants of Babylon laughed at the siege, because the strong and lofty walls could not be taken by storm, and the siege would not hurt them, for they had provisions for more than twenty years. Cyrus also soon convinced himself that the city could not be taken by the means which he was employing, and resolved to draw off the Euphrates, which traverses the city in a stream two stadia (1200 feet) in breadth, and twice the height of a man in depth. For this object he threw a rampart round the whole city, with a very broad and deep trench before it on the side towards the city. This great work was apportioned to the different parts of the army, and the time occupied in it was calculated at a year. Where the trenches approached the river the earth was not excavated, so that the water would not flow into the trenches. When Cyrus perceived that the Babylonians celebrated a festival at a fixed time, at which they feasted for the whole night, he caused the earth which separated the river from the trenches above the city to be cut through by a multitude of men as soon as it was dark; the water at once ran into the trenches, and the river sank so low that it could be forded. The river now opened a way into the city, and Cyrus bade his troops enter by its bed. They would find the inhabitants drunk and asleep, without any organization for resistance, and when they found the enemy in the city they would lose all their courage. If the Babylonians, nevertheless, attempted to hurl down missiles from the roofs, the houses could be burned, and they would take fire readily, as the doors were of palm-wood covered with bitumen. A separate troop of the Persian army, which Gobryas led, had orders to make their way to the palace of the king as quickly as possible. The Persians entered, and cut down the inhabitants whom they found; others saved themselves by flight. The watch of the palace were drinking by a bright fire before the gates, which were closed. They were surprised and cut down. When the noise of the fight was heard inside the palace, the king sent to inquire what was the meaning of the tumult. But as soon as the gate was opened the Persians forced their way into the palace; the king and those around him drew their swords, but succumbed to numbers, and were killed. Meanwhile Cyrus had despatched his cavalry along the streets, sending with them men skilled in the Syrian language, who proclaimed that every one who remained in his house would be uninjured; all who showed themselves in the streets would be put to death. Thus the city quickly passed into the hands of the Persians. The gates of the citadel were opened the next morning, when the dawn of light showed them the Persians in possession of the city.[71]