PIREUS, in Ancient Geography, a celebrated port to the W. of Athens, consisting naturally of three harbours or basins, which lay neglected till Themistocles put the Athenians on making it a commodious port; the Phalerus, a small port, and not far from the city, being what they used before that time. The Piræus, as Athens flourished, became the common emporium of all Greece. Hippodamus, an architect, celebrated as the inventor of many improvements in house-building, besides other monuments of his genius, was employed to lay out the ground. Five porticoes, which, communicating with one another, formed the Long Portico, were erected by the ports. Here was an agora or market-place, and, farther from the sea, another called hippodamia. Beside the vessels were dwellings for the mariners. A theatre was opened, temples were raised, and the Piræus, which surpassed the city in utility, began to equal it in dignity. The cavities and windings of Munychia, natural and artificial, were filled with houses; and the whole settlement, comprehending Phalerus and the ports of the Piræus, with the arsenals, the store-houses, the famous armoury of which Philo was the architect, and the sheds for 300, and afterwards 400 triremes, resembled the city of Rhodes, which had been planned by the same Hippodamus. The ports, on the commencement of the Peloponnesian war, were secured with chains. Sentinels were stationed, and the Piræus was carefully guarded.
The Piræus was reduced with great difficulty by Sylla, who demolished the walls, and set fire to the armoury and the arsenals. In the civil war it was in a defenceless condition. Calenus, lieutenant of Cæsar, seized it, invested Athens, and ravaged the territory of the state. Strabo, who lived under the emperors Augustus and Tiberius, observes that the many wars had destroyed the long walls, with the fortress of Munychia, and had contracted the Piræus into a small settlement by the ports and the temple of Jupiter the Saviour. (See ATHENS.)