Arch of Titus
The Arch of Titus is a triumphal arch with a single arched opening, located on the Via Sacra just to the south-east of the Forum in Rome. It was constructed shortly after the death of the emperor Titus (born AD 41, emperor 79-81).
The arch commemorates Titus' capture and sack of Jerusalem in 70, which effectively terminated the Jewish War which had begun in 66 (the Romans did not achieve complete victory until the fall of Masada in 73).
The Arch of Titus is in three bays with an ABA rhythm, articulated with a massive order of attached columns that stand on a high ashlar basement. The capitals are Corinthian, but with prominent volutes of the Ionic order scrolling out above the acanthus foliage, the earliest example of the Composite order. Above the main cornice rises a high weighty attic on which is a central tablet bearing the dedicatory inscription. The entablatures break forward over the columns and in the wide central bay. Flanking the central arch, the side bays now each contain a shallow niche like a blind aedicular window, a discreet early 19th century restoration.
The soffit of the archway is deeply coffered with a relief of the apotheosis of Titus at the center. The sculptural program also includes two panel reliefs that line the passageway. Both commemorate the joint triumph celebrated by Titus and his father Vespasian in the summer of 71. One of the panels depicts the spoils taken from the Temple, while the other depicts Titus as triumphator attended by various genii and lictors. The soffit of the arch depicts the apotheosis of Titus. The sculpture of the outer faces of the two great piers was lost when the Arch of Titus was incorporated in medieval defensive walling. The attic of the arch was originally crowned by more statuary, perhaps of a quadriga pulled by elephants.
Based on the style of sculptural details, Domitian's favored architect Rabirius, sometimes credited with the Colosseum, may have executed the arch. Without contemporary documentation, however, attributions of Roman buildings on basis of style are considered shaky.
The Arch of Titus has provided the general model for many of the triumphal arches erected since the 16th century.
The inscription in Roman square capitals reads:

SENATVS
POPVLVSQVE·ROMANVS
DIVO·TITO·DIVI·VESPASIANI·F(ILIO)
VESPASIANO·AVGVSTO

Which means "The Senate and People of Rome (dedicate this) to the divine Titus Vespasianus Augustus, son of the divine Vespasian."
In a later era, it was the place of a yearly oath of loyalty, forced by the Pope on the Jews of the Roman Ghetto.
 

From: www.wikipedia.org