In the west the recuperation of Carthage since the Second Punic War had given amazing proof of her vitality. With Hannibal in exile, his political opponents were in power, seeking to gain good relations with Rome, rather than displaying Hannibal's open hostility.
But roman friendship was hard to gain. All Italy, as well as Rome itself had suffered irreparably in the long war.
To add to Carthage's troubles Masinissa, who was king of Numidia and a close Roman ally, was not only harassing their borders but gradually clawing land away from them, claiming these territories to be his under the peace treaty signed by Carthage after its defeat at Zama.
Closer and closer Masinissa's horsemen came within striking distance of the southward caravan routes of Carthage, endangering her trade.
Carthage alas complained to Rome. So, in 150 BC a Roman commission of inquiry was sent to Africa to sort matters out between Carthage and Numidia. But the leader of the commission was Marcus Cato, whose hatred and fear of Carthage became legendary.
In spite of the sanctions and conditions imposed on Carthage there was a possibility that it might rise again and once more wreak havoc on the Roman Empire. And Cato the Elder believed this more than anyone else. He sought Carthage's destruction like no-one else. It is said that he even contrived to drop a Lybian fig on the floor of the senate. Then, as the senators admired its size, he warned that the land from which it came was only three days away by sea. Furthermore he famously incorporated the words 'Carthage must be destroyed !' (Delenda Carthago !) in every speech he held in the senate, no matter what the subject of the matter debated was.
Cato the Elder
With this Cato the Elder leading the commission of inquiry it was obvious from the beginning that the commission would find in favour of Masinissa. The result was yet further attacks by Numidian horsemen. Carthage lost patience and responded, fighting back.
No doubt, this was exactly what Cato the elder had hoped for, as it breached the terms signed by Carthage after its defeat in the Second Punic War. For Carthage was not allowed to take up arms without Roman permission.
The senate, egged on by Cato, and having already made plans for such an occurrence, voted for war. They sent out a trained army of 80'000 infantry and 4'000 cavalry to whom they had given orders not to occupy Carthage, but far more to raze it to the ground.
Everything short of the worst was offered by the Carthaginian government to avert war, but in vain. The Roman commanders had their orders. The effect was that the desperate war party took control of the city of Carthage. Moderate men, who had tried to save peace, were massacred together with the Italian residents. A army was raised from the city itself and its neighbouring towns and tribes.
Meanwhile the Roman army, having allowed the Carthaginians too much time to organize, was losing more men through sickness (due to camping out in marshes) than it lost by fighting the enemy.
After two years of blundering, Scipio Aemilianus was elected to be consul and commander in Africa (147 BC). With good leadership Roman victory was inevitable for Carthage was a mere shadow of the power she had once been.
The northern suburbs of Carthage were soon occupied without difficulty. Then Scipio undertook huge engineering works to close the harbour entrance of Carthage and thereby cut off the supplies coming in by sea.
He waited for winter to pass before he ordered an assault on the city. The charge succeeded and they broke into the city, but still needed six days and six nights to fight their way from house to house.
Alas the remaining Carhaginian resistance in the citadel refused to surrender and was burned.
The Third Punic War had lasted merely three years. Carthage was devastated, utterly destroyed. However, Carthage was duly defeated and destroyed. The 50'000 survivors of the siege were all sold into slavery.
Carthage was levelled with the ground by the Roman army, cursed and ploughed over. The same fate befell other cities in Africa.
The city Utica was now made capital of the Roman province of Africa. Numidia remained a free ally of Rome, but with Masinissa having died, it was now in the hands of his three quarreling sons and hence posed no threat. Tripolitania also came under Roman rule, but was purposely kept separate from the African province.