Justinian selects one of his most trusted…

The year 533 sees the last recorded festival (including classical theater performances) in a greatly diminished Rome.

…the fleet spends five days at Heraclea Perinthus waiting for horses and a further four days at Abydos due to lack of wind.

The picture is less clear on the Vandal side.

The Vandal army is not a professional and mostly volunteer force like the East Roman army, but comprises every able-bodied male of the Vandal people.

Hence, modern estimates on the available forces vary along with estimates on the total Vandal population, from a high of between thirty thousand and forty thousand men out of a total Vandal population of at most two hundred thousand people (Diehl and Bury), to as few as twenty-five thousand men—or even twenty thousand, if their losses against the Moors are taken into account—for a population base of one hundred thousand (Hughes).

Despite their martial reputation, the Vandals have grown less warlike over time, having come to lead a luxurious life amid the riches of Africa.

In addition, their mode of fighting is ill suited to confronting Belisarius' veterans: the Vandal army is composed exclusively of cavalry, lightly armored and armed only for hand-to-hand combat, to the point of neglecting entirely the use of bows or javelins, in stark contrast to Belisarius' heavily armored cataphracts and horse archers.

The Vandals are also weakened by the hostility of its Roman subjects, the continued existence among the Vandals of a faction loyal to Hilderic, and by the ambivalent position of the Moorish tribes, who watch the oncoming conflict from the sidelines, ready to join the victor and seize the spoils.

The imperial invasion fleet had left the Dardanelles on July 1, and crossed the Aegean Sea to the port of Methone, where it had been joined by the last contingents of troops.

Belisarius had taken advantage of an enforced stay there due to a lull in the wind to train his troops and acquaint the disparate contingents with each other.

It was at Methone, however, that five hundred men died of dysentery caused by moldy bread.

According to Procopius, the responsibility fell on John the Cappadocian, who had cut costs by baking it only once, with the result that the bread had gone bad.

Justinian was informed, but John does not appear to have been punished.

Belisarius took steps to remedy the situation, and the army had soon recovered.

From Methone, the fleet sailed up the Ionian Sea to Zacynthus, whence they crossed over to Italy.

The crossing took longer than expected due to lack of wind, and the army had suffered of lack of fresh water when the supplies they had brought aboard went bad.

Eventually, the imperial fleet had reached Catania in Sicily, from where Belisarius had sent Procopius ahead to Syracuse to gather intelligence on the Vandals' activities.

By chance, Procopius had met a merchant friend of his there, whose servant had just arrived from Carthage.

The latter had informed Procopius that not only are the Vandals unaware of Belisarius' sailing, but that Gelimer, who had just dispatched Tzazon's expedition to Sardinia, is away from Carthage at the small inland town of Hermione.

Procopius quickly informs Belisarius, who immediately orders the army to re-embark and set sail for the African coast.

In early September, after sailing by Malta, the invasion force reaches Cape Caputvada on the western shore of modern Tunisia some 162 Roman miles (240 km) south from Carthage.

When the Roman fleet reaches Africa, a council is held aboard Belisarius' flagship (The Vandalic War, I.15), where many of his officers advocate an immediate attack on Carthage itself, especially since it is the only fortified city in the Vandal realm, the walls of the other cities having been torn down to prevent a rebellion.

Belisarius, however, mindful of the fate of the 468 expedition and wary of an encounter with the Vandal fleet, speaks against it.

Thus the army disembarks and builds a fortified camp to spend the night.

Belisarius knows that success for his expedition relies on gaining the support of the local population, which has largely retained its Roman identity and to which he presents himself as a liberator.

Thus on the next day of the landing, when some of his men steal some fruit from a local orchard, he severely punishes them, and assembles the army and exhorts them to maintain discipline and restraint towards the native population, lest they abandon their Roman sympathies and go over to the Vandals.

Belisarius' pleas bear results, for, as Procopius reports (The Vandalic War, I.17), "the soldiers behaved with moderation, and they neither began any unjust brawls nor did anything out of the way, and [Belisarius], by displaying great gentleness and kindness, won the Libyans to his side so completely that thereafter he made the journey as if in his own land".

Now the Roman army begins its march north, following the coastal road.

Belisarius detaches three hundred horse under John the Armenian as an advance guard some three miles (four-and-a-half kilometers) in front of the main army, while the six hundred Huns cover the army's left flank.

Belisarius himself with his bucellarii leads up the rear, to guard against any attack from Gelimer, who is known to be in the vicinity.

The fleet follows the army, sailing along the coast.

The first town they encounter is Syllectum, which is captured by a detachment under Boriades by a ruse.

In an attempt to sow division among the Vandals, Belisarius gives a letter written by Justinian and addressed to the Vandal nobles to a captured Vandal messenger, in which the emperor claims to be campaigning on behalf of the legitimate king Hilderic against the usurper Gelimer.

As the messenger is too afraid to deliver the letter, this ploy comes to nothing.

Gelimer, upon learning of the Romans' arrival, immediately notifies his brother Ammatas in Carthage to assemble the Vandal forces in the vicinity, as well as to execute Hilderic and his relatives, while his secretary Bonifatius is ordered to load the royal treasure on a ship and sail for Spain if the Romans win.

Deprived of his best troops, which are with Tzazon, Gelimer contends himself with shadowing the northward march of the Roman army, all the while preparing a decisive engagement before Carthage, at a place called Ad Decimum ("at the tenth [milepost]") where he has ordered Ammatas to bring his forces.

The Romans advance through Thapsus, Leptis Parva and Hadrumetum to Grasse, where for the first time they engage in a skirmish with the scouts of Gelimer's army.

After exchanging blows, both parties retire to their camps.

From Grasse, Belisarius turns his army westwards, cutting across the neck of the Cape Bon peninsula.

This is the most dangerous part of the route to Carthage, with the fleet out of sight.

Thus, on the morning of September 13, the tenth day of the march from Caputvada, the Roman army approaches Ad Decimum.

Here Gelimer plans to ambush and encircle them, using a force under his brother Ammatas to block their advance and engage them, while two thousand men under his nephew Gibamund will attack their left flank, and Gelimer himself with the main army will attack from the rear and completely annihilate the Roman army.

In the event, the three forces fail to synchronize exactly: Ammatas arrives early and is killed as he attempts a reconnaissance with a small force by the Roman vanguard, while Gibamund's force is intercepted by the Hunnic flank guard and is utterly destroyed.

Unaware of all this, Gelimer marches up with the main army and scatters the Roman advance forces present at Ad Decimum.

Victory might have been his, but he then comes upon his dead brother's body, and apparently forgets all about the battle.

This gives Belisarius the time to rally his troops, come up with his main cavalry force and defeat the disorganized Vandals.

Gelimer with the remainder of his forces flees westwards to Numidia.

The Battle of Ad Decimum ends in a crushing Roman victory, and Carthage lies open and undefended before Belisarius.

It is only by nightfall, when John the Armenian with his men and the six hundred Huns rejoin his army, that Belisarius realizes the extent of his victory.

The cavalry spends the night at the battlefield.

In the next morning, as the infantry (and Antonina) catch up, the whole army makes for Carthage, where it arrives as night is falling.

The Carthaginians have thrown open the gates and illuminated the city in celebration, but Belisarius, fearing a possible ambush in the darkness and wishing to keep his soldiers under tight control, refrains from entering the city, and encamps before it.

In the meantime, the fleet has rounded Cape Bon and, after learning of the Roman victory, has anchored at Stagnum, some seven and a half kilometers from the city.

Ignoring Belisarius' instructions, Calonymus and his men proceed to plunder the nearby merchant settlement of Mandriacum.

Belisarius on the morning of the next day, September 15, draws up the army for battle before the city walls, but as no enemy appears, he leads his army into the city, after again exhorting his troops to show discipline.

The Roman army receives a warm welcome from the populace, which is favorably impressed by its restraint.

While Belisarius himself takes possession of the royal palace, seats himself on the king's throne, and consumes the dinner which Gelimer has confidently ordered to be ready for his own victorious return, the fleet enters the Lake of Tunis and the army is billeted throughout the city.

The remaining Vandals are rounded up and placed under guard to prevent them from causing trouble.

Belisarius dispatches Solomon to Constantinople to bear the emperor news of the victory, but expecting an imminent reappearance of Gelimer with his army, he loses no time in repairing the largely ruined walls of the city and rendering it capable of sustaining a siege.

Belisarius has remained in Carthage strengthening its walls during the past weeks, while Gelimer has established himself and the remnant of his army at Bulla Regia.

Gelimer has managed to cement the loyalty of the locals to his cause by distributing money, and sends messages recalling Tzazon and his men from Sardinia, where they have been successful in reestablishing Vandal authority and killing Godas.

While waiting for Tzazon's arrival, the Vandal king's army also increases by the arrival of more and more fugitives from the battle of Ad Decimum, as well as by a contingent of his Moorish allies.

Most of the Moorish tribes of Numidia and Byzacena, however, send embassies to Belisarius, pledging allegiance to the Empire.

Some even offer hostages and ask for the insignia of office traditionally awarded to them by the emperor: a gilded silver staff and a silver crown, a white cloak, a white tunic, and a gilded boot.

Belisarius has been furnished by Justinian with these items in anticipation of this demand, and duly dispatches them along with sums of money.

Nevertheless it is clear that, as long as the outcome of the war remains undecided, neither side can count on the firm loyalty of the Moors.

During this period, messengers from Tzazon, sent to announce his recovery of Sardinia, sail into Carthage unaware that the city has fallen and are taken captive, followed shortly after by Gelimer's envoys to Theudis, who had reached Spain after the news of the Roman successes had arrived there and hence failed to secure an alliance.

Belisarius is also reinforced by the Roman general Cyril with his contingent, who had sailed to Sardinia only to find it once again in possession of the Vandals.

As soon as Tzazon receives his brother's message, he leaves Sardinia and lands in Africa, joining up with Gelimer at Bulla.

The Vandal king now determines to advance on Carthage.

His intentions are not clear; the traditional interpretation is that that he hoped to reduce the city by blockading it, but Ian Hughes believes that, lacking the reserves for a protracted war of attrition, he hoped to force Belisarius into a "single, decisive confrontation".

The Vandal army approaching the city cuts the aqueduct supplying it with water, and attempts to prevent provisions from arriving in the city.

Gelimer also dispatches agents to the city to undermine the loyalty of the inhabitants and the imperial army.

Belisarius, who is alert to the possibility of treachery, sets an example by impaling a citizen of Carthage who had intended to join the Vandals.

The greatest danger for defection comes from the Huns, who are disgruntled because they had been ferried to Africa against their will and fear being left here as a garrison.

Indeed, Vandal agents have already made contact with them, but Belisarius manages to maintain their allegiance—at least for the moment—by making a solemn promise that after the final victory they will be richly rewarded and allowed to return to their homes.

Their loyalty however remains suspect, and, like the Moors, the Huns probably await to see who will emerge as the victor and rally to him.