The Siege of Carthage was the main engagement of the Third Punic War and was fought between Carthage and Rome. It consisted of the nearly-three-year siege of the Carthaginian capital, Carthage (a little north east of modern Tunis). In 149 BC a large Roman army landed at Utica in North Africa. The Carthaginians hoped to appease the Romans, but despite the Carthaginians surrendering all of their weapons, the Romans pressed on to besiege the city of Carthage. The Roman campaign suffered repeated setbacks through 149 BC, only alleviated by Scipio Aemilianus, a middle-ranking officer, distinguishing himself several times. A new Roman commander took over in 148 BC, and fared equally badly. At the annual election of Roman magistrates in early 147 BC public support for Scipio was so great that the usual age restrictions were lifted to allow him to be appointed consul and commander in Africa.
Scipio’s term commenced with two Carthaginian successes, but he tightened the siege and commenced a construction of a large mole to prevent supplies from getting into Carthage via blockade runners. The Carthaginians had partially rebuilt their fleet and it sortied, to the Romans’ surprise; after an indecisive engagement the Carthaginians mismanaged their withdrawal and lost many ships. The Romans then built a large brick structure in the harbour area which dominated the city wall. In the spring of 146 BC the Romans launched their final assault and over seven days systematically destroyed the city and killed its inhabitants; only on the last day did they take prisoners – 50,000, who were sold into slavery. The formerly Carthaginian territories became the Roman province of Africa with Utica as its capital. It was a century before the site of Carthage was rebuilt as a Roman city.
The city of Carthage itself was unusually large for the time, with a population estimated at 700,000. It was strongly fortified with walls of more than 35 kilometres (20 miles) circumference. Defending the main approach from the land were three lines of defences, of which the strongest was a brick-built wall 9 metres (30 ft) wide and 15-20 metres (50-70 ft) high with a 20-metre-wide (70 ft) ditch in front of it. Built into this wall was a barracks capable of holding over 24,000 soldiers. The city had few reliable sources of ground water, but possessed a complex system to catch and channel rainwater and a large number of cisterns to store it.
The Carthaginians raised a strong and enthusiastic force to garrison the city from their citizenry and by freeing all slaves willing to fight. They also formed a large strong field army, commanded by Hasdrubal, freshly released from his condemned cell. This army was based at Nepheris, 25 kilometres (16 miles) south of the city. Appian gives the strength of the Roman army which landed in Africa as 84,000 soldiers; modern historians estimate it at 40,000-50,000 men, of whom 4,000 were cavalry.