Berytus (Colonia Iulia Augusta Felix Berytus) was a Roman colonia that was the center of Roman presence in the eastern Mediterranean shores south of Anatolia. Roman Berytus (modern Beirut) was the capital of Phoenicia during Roman times.
In 140 BC the Phoenician village called "Biruta" was destroyed by Diodotus Tryphon in his contest with Antiochus VII Sidetes for the throne of the Macedonian Seleucid monarchy. Later it was soon rebuilt on a more conventional Hellenistic plan and renamed Laodicea in Phoenicia (Greek: Λαοδίκεια ἡ ἐν Φοινίκῃ) or Laodicea in Canaan in honor of a Seleucid Laodice.
The city was conquered by the Romans of Pompey in 64 BC and renamed "Berytus", as a reference to the name of the old original phoenician port-village. The city was assimilated into the Roman Empire, veteran soldiers were sent there, and large building projects were undertaken.
...(Berytus) was made a Roman colony about 14 B.C. Herod the Great, Agrippa I and II, and Queen Berenice built exedras, porticos, temples, a forum, a theater, amphitheater, and baths here. In the 3d c. A.D. the city became the seat of a famous school of law and continued to flourish until the earthquake of A.D. 551 ravaged the city....Its streets, laid out on a grid plan, are spaced at roughly the same intervals as those of Damascus and Laodicea. The new Roman city spread farther S and W (of the port), with its Forum near the (actual) Place de l'Etoile. On its N side was a civic basilica 99 m long with a Corinthian portico of polychrome materials..., dating from the 1st c. A.D. Some large baths have been uncovered on the E slope of the (actual) Colline du Sérail, and the hippodrome lay on the NW side of the same hill. Some villas in a S suburb facing the sea had mosaic floors (now in the Beirut Museum).Some 12 km upstream on the Beirut river are the ruined arches of an aqueduct.