In the early 3rd century BC, Rome's power started to frighten Taranto, so the Tarantines decided to call for help from Pyrrus, king of Epirus. In 281 BC, Roman legions entered Taranto and plundered it. Pyrrhus decided to help Taranto because he was in debt to them. In the spring of 280 BC, he landed in Italy with 20,000 phalanxes, 500 peltasts, 2,000 archers, 3,000 elite cavalry from Thessaly, and 20 war elephants. The Romans mobilized eight legions totalling about 80 000 soldiers, and divided into 4 armies. The battle of Heraclea was won by Pyrrhus, but the casualties were very high. Finally Pyrrhus and the Tarentines were defeated by the Romans in the battle of Beneventum.
In 122 BC a Roman colony was founded next to Taranto, Neptunia, and populated by Roman colonists, but it was later unified to the main centre when Taranto become a municipium in 89 BC. During the late Republic and all the Roman Empire, Taranto was a simple provincial city. Taranto followed the story of Italy during the late Empire, becoming part of the Byzantine Empire in 540, and was ruled by them until 662 whem it was conquered by the Lombards of the Duchy of Benevento. In the 8th century AD Saracens began their raids against Southern Italy, occupying Taranto for forty years, until it was reconquered by the Byzantines in 880. The city suffered from other Saracen raids, as in 922 and again on 15 August 927, when the Saracens, led by the Slavic Sabir, conquered and destroyed the city, enslaving and deporting to Africa all the survivors. In 967 the Byzantine emperor Nicephorus II Phoca realizing the startegic importance of the area rebuilt Taranto. In the 11th century was characterized by a bloody struggle between Normans and Byzantines for the rule over the Tarentine and Barensis lands. Taranto was finally conquered by the Normans and became the capital of a Norman principality for almost 4 centuries.
In 1465 Ferdinand I of Naples unitied Taranto to the Kingdom of Naples. In March 1502, the Spanish fleet of Ferdinand II of Aragon, allied to Louis XII of France, seized the port of Taranto, and conquered the city. In the 1746 census Taranto had 11,526 inhabitants, all of them living on the Small Island. From 1799 to 1815 Taranto joined the Parthenopaean Republic, and among the French officers in the city there was also novelist Chordelos de Laclos. With the fall of Napoleon Southern Italy and Tarant, returned under Bourbons rule, forming the Kingdom of the Two Sicilies. Then in 1861 the whole Southern Italy was annexed to the Kingdom of Sardinia, which became the Kingdom of Italy. In November 1940, during World War II, the Italian ships at anchor in Mar Grande and Mar Piccolo were severely damaged by British naval forces in the so-called Battle of Taranto and on September 9, 1943 British forces landed near the port on as part of the Allied invasion (Operation Slapstick).