market and meeting place in ancient Roman towns in Italy and later in the provinces, corresponding to the Greek agora. By extension the word forum often indicates the meeting itself in modern usage. The forum was usually square or rectangular in shape and had, among other buildings, a basilica with shops, the public treasury, the curia, and a prison; under Greek influence colonnades were introduced.
The old Roman Forum extended into a marshy valley from Capitoline Hill along the Palatine Hill. When, much later, the Basilica of Constantine was added it reached almost to the Colosseum. The valley between the hills was crossed by a small stream emptying into the Tiber, which drained the area and was canalized underground (probably in the 6th cent. B.C.) to become the great sewer, the Cloaca Maxima (a portion of which still exists). At the south end of the Forum was the house of the vestal virgins and nearby the temple of Vesta. West of the temple, as an entrance to the Forum proper, was the Arch of Augustus, having on one side the temple of deified Julius Caesar and on the other that of Castor and Pollux. Behind it was a building, now the Church of Santa Maria Antiqua, with fine 8th-century frescoes. Along the southwest side of the Forum was the Basilica Julia, and along its northeast side were the Basilica Aemilia and the curia, where the senate met. The Forum was closed to the northwest by the Arch of Septimius Severus and by the rostra (platforms adorned with beaks of captured vessels), from which tribunes, consuls, and orators made their speeches. Beyond them, toward Capitoline Hill, were temples, among them the Temple of Concord and the temple of Saturn, housing the treasury.
In imperial times the old Forum became inadequate; the emperors built new forums to the northeast, from the Basilica of Constantine to the valley between the Capitoline and Quirinal. On the southeast were the Forum of Vespasian with the Temple of Peace surrounded by a colonnade; next the Forum of Nerva; then that of Augustus with the temple of Mars. Southwest was the smaller Forum of Julius Caesar, a colonnade enclosing the temple of Venus. Beyond the Forum of Augustus was the Forum of Trajan, a vast colonnaded square; then the Basilica Ulpia; then the two libraries with, between them, the Column of Trajan, which is still standing. The temple of Trajan closed the Emperors' Forums to the northwest.
In the 4th cent., the decay of the old Forum began; earthquakes, fires, and the barbarian invasions completed its destruction. In the Middle Ages materials from the forums were used to build new monuments throughout the city. Only in the 19th and 20th cent. were systematic excavations made to bring to light what was left. The forums are now, with the Palatine and Colosseum, an imposing complex of ruins, testifying to the magnificence of ancient Rome.