by Hughes, Ian
With these conclusions, one option open to him was to advance immediately and try to attack the Byzantines from the rear in the open space around Carthage. On the clear ground he would quickly be seen and so lose the advantage of surprise. Furthermore, if he did not know already, he would guess that the enemy outnumbered his available forces. Such an attack was not a realistic option. The alternative was to wait until nightfall and send messengers into the town to gain a clearer understanding of what had happened. Then he could decide what to do; either retreat until Tzazon returned from Sardinia or mount an attack in conjunction with the forces remaining in the city. This is a more likely explanation for his delay at this vital moment in the battle. As he was arranging matters, asking for advice and deciding upon his options, disaster struck.
Phase IV: The Arrival of Belisarius and Defeat of Gelimer
At this point Belisarius arrived with his organised troops and swiftly attacked the disordered Vandals from an unexpected direction. Unable to withstand the assault, the Vandals fled, but not in the direction of Carthage. They were still unsure of events and it was probable that there was a substantial Byzantine force on the road to Carthage that could trap them. Instead, they fled off-road towards the relative safety of the Plains of Boulla and the road leading to Numidia. Gelimer had recently made alliances with some of the Moorish tribes in the area, so his decision was valid. This was to be a costly, though understandable, mistake. Although there was no way he could have known, his forces would easily have brushed aside John’s 300 men, who were scattered and intent on gathering plunder, and so have reinforced the garrison at Carthage.
As Gelimer headed away from the city, there were now not enough troops in Carthage either to withstand a Byzantine assault or to stop the city’s population from opening the gates to the victor. Furthermore, the walls had not been repaired and so would not withstand an attack without a large number of defenders. The Battle of Ad Decimum was over and Carthage lay open to the victor. Belisarius had won.
The Generalship of Belisarius and Gelimer
The standard interpretation of the battle has been that Gelimer’s strategy was too complex, with his forces arriving at badly-timed intervals, allowing the Byzantines to crush each small group individually. Conversely, Belisarius is the genius that takes advantage of Gelimer’s indecision and inability to control his troops to win the day. Based largely upon Procopius’ account, which was written to acclaim Belisarius’ talents as a general, the interpretations are too polarised and based upon the misleading factors already highlighted in the account of the battle.
Turning first to Gelimer, he immediately reaped the negative rewards of Vandal policy towards Catholics: the natives were willing to support Belisarius and withdrew their loyalty from Gelimer and, more importantly, failed to volunteer information at a critical point in the battle. His plan at Ad Decimum was excellent and made with commendable speed. It made good use of his background knowledge of the terrain and the movement rates of both his own and the Byzantine troops: he knew where and when he wanted to fight, and it was only because of Ammatus’ mistake that this did not occur.
If Ammatus had left at the correct time with all of his forces, it is likely that he would have forced John to retire back along the valley. Belisarius would probably have moved forward and attempted battle with Ammatus, who would have been heavily outnumbered. Whilst Belisarius was deploying and preparing for battle, Gelimer would have arrived and Belisarius would have been in grave danger. Furthermore, Gelimer could not have foreseen that a small force of 600 Huns would have destroyed the 2,000 men under his nephew Gibamundus. Although this was to have no effect on the battle at Ad Decimum itself, it still highlights the unexpected course that all of the events took that day.
The arrival of Gelimer and the ease with which his men beat the foederati shows that the Vandals were capable troops who were willing to fight. More than anything, the battle emphasises the importance of luck upon the battlefield. The Byzantines were lucky to beat Ammatus; they were lucky to beat Gibamundus; and they were extremely lucky in that Gelimer halted in confusion at the unexpected find of his brother’s body. At Ad Decimum, luck was definitely against Gelimer.
If Gelimer was unlucky, then it would be tempting to assume that Belisarius was simply lucky, for all of the reasons just listed. Yet there is more to his victory than blind chance. His decision to restrain the troops in their dealings with the natives was crucial. This enabled him to advance without having to lay siege to towns and secure in the knowledge that no armed forces would emerge from them to attack his rear. This allowed him to concentrate solely upon the Vandals. Furthermore, on the day of the battle the Libyans were willing to give his troops information, which they then withheld from Gelimer.
Belisarius’ order of march also shows good judgement. The advance guard and the flank guard were crucial to avoid him being taken by surprise. Moreover, his positioning himself at the rear displays recognition that the main Vandal thrust was likely to come from the south.
His decision to establish a camp and leave the majority of the infantry to guard it is also commendable. He needed to gather information and the infantry could easily become a liability if a large number of enemy cavalry were present. Yet it is when he halted and began to build the camp that he made a major mistake that could have proved costly. He did not immediately send messengers to inform either John or the Huns that he had stopped. This allowed them to continue their advance, leaving them dangerously isolated and vulnerable. Furthermore, when he finally left the camp, he sent the foederati ahead to contact John, who by this time was already engaged in battle. There is no evidence that he also sent word to the Huns to inform them of the change in circumstances. With only a slight change in the course of events, both John and the Huns could have been heavily defeated. Gelimer’s strategy could easily have become a reality.
Having censured Belisarius for these mistakes, we should note that when he was joined by the routing foederati and guard he had the presence of mind to stay calm, stop them, rebuke them and then ask for information. He also had the ability to see that the situation could be turned to his advantage. Realising that he had the opportunity to strike Gelimer whilst he was uninformed and off guard, he swiftly changed his plans and attacked. There is no point in being lucky if you do not have the wit to take advantage of your good fortune.
With the above factors in mind, it is possible to conclude that Gelimer was extremely unlucky and could not have foreseen the events that happened that day. Conversely, although Belisarius was extremely lucky, he should be commended for his sound judgement and quick thinking in the heat of battle. He was about to reap the rewards of the victory.
Carthage
John with the Byzantine cavalry and the 600 Huns under Sinnion and Balas returned and rejoined Belisarius at Ad Decimum with the onset of dusk. It was only now that Belisarius was to gain a full insight into all of the events of the day and comprehend the scale of his victory. The reunited cavalry passed the night at Ad Decimum.
On the following day the infantry left their camp and joined Belisarius, bringing Antonina with them. The whole army regrouped and advanced to Carthage, arriving as night was falling. Belisarius had them camp in the open even though the gates were open and the citizens lit many lights to illuminate the scene. He was still worried in case the Vandals had set an ambush in the city streets, and was also aware that his own troops might use the cover of night to sack the city unobserved should they be allowed in.
Having sailed around Cape Bon, the fleet was at first unaware of events, so sent men to the city of Mercurium for information. Upon learning of the victory, they approached Carthage, but decided to anchor at Stagnum, forty stades (approximately 4½ miles) from the city. Once anchored, Calonymus the admiral appears to have gathered a small group of sailors and ignored Belisarius’ instructions. They proceeded to plunder the property of merchants at nearby Mandriacum.
On the morning of day six, Belisarius drew the a
rmy up in battle formations – he was still concerned about the possibility of a Vandal ambush – and reminded the troops to leave the citizens unharmed. The Byzantines finally entered the city, Belisarius occupying the palace of Gelimer and receiving delegations from the citizens. Almost immediately, there was an outcry and the merchants whose property had been taken demanded restitution. According to Procopius, Calonymus swore to return the goods but never fulfilled his oath. However, the merchants were appeased and calm restored.
Belisarius and his staff ate the meal that had been prepared in expectation of Gelimer’s return whilst the troops were billeted around the city. Such billeting was the norm in a peacefully-occupied city, and the exceptional behaviour of the troops helped to cement the loyalty of the majority of the Carthaginians. In the afternoon Belisarius displayed the policy he would maintain towards the defeated Vandals. There were many of them around the city, staying in sacred buildings for sanctuary due to fear of retribution. Belisarius made pledges guaranteeing their safety and they were rounded up, disarmed and led to places of safety.
Belisarius also ordered the refortification of Carthage. The city walls had become ruinous in many places and so were useless as a means of defence; therefore Belisarius paid the native Carthaginians to build a ditch with stakes around the wall. Once this was complete, he felt secure enough to order work begun on repairing the decayed portions of the walls.
For the next few weeks Belisarius remained in Carthage to oversee the work, sending Solomon to Constantinople with an account of the events thus far. And his luck stayed with him. Whilst the events described above had been transpiring in Africa, Gelimer’s brother, Tzazon, had completed the reconquest of Sardinia, killing Godas in the process. Unaware of the loss of Carthage, he dispatched messengers with details of his victory. These men sailed into Carthage and were captured. At around this point, the Byzantine general Cyril also sailed into the harbour, having journeyed to Sardinia and separately discovered that Tzazon was victorious and Godas dead. The extra men he brought to Carthage would have been a welcome reinforcement to Belisarius.
Additionally, the envoys previously sent to Spain to ask King Theudis of the Visigoths for an alliance had reached the Visigothic king. They had travelled very slowly and Theudis was informed of the loss of Carthage before they reached him. Naturally, he refused to make an alliance. Rebuffed, the envoys also returned to Carthage and were captured by Belisarius. In this way Belisarius was kept in touch with the larger events in the Mediterranean. Gelimer, on the other hand, was still awaiting information concerning either his envoys or his brother Tzazon.
Although by his retreat to Boulla Gelimer may have been counting on his new Moorish allies, the majority of the Moors did not want an alliance with him. Many sent envoys to Belisarius, some even including hostages, asking for the traditional symbols of office given to them by a Byzantine emperor, and promising to fight as Belisarius’ allies. Justinian had evidently been aware of such an eventuality, and so had furnished Belisarius with the insignia before the fleet sailed. Belisarius sent the items plus large sums of money, but the Moors took no active part in the war and were to remain neutral until the outcome was inevitable.
In the period of calm which followed the battle at Ad Decimum, Gelimer did not remain idle. He distributed money amongst the farmers around the plain of Boulla, enticing many to maintain their allegiance to the Vandals. He further announced a fixed sum of cash for the head of every Byzantine brought to him. Many heads were produced, and he appears to have believed that the Byzantine army itself was gradually being eroded. However, they were the heads of Byzantine slaves and servants out of the city on business of their own. The Byzantine troops kept their heads and remained within the city walls.
Gelimer was soon joined by his Moorish allies, although they do not seem to have provided a sizeable force. As seen above, the majority of the Moors were biding their time before openly declaring their allegiance. Gelimer sent messages to his brother in Sardinia, informing him of events and recalling him to Africa. Tzazon sailed to Africa and then travelled across land to meet Gelimer at Boulla.
With the return of Tzazon and his forces, and with his own forces slowly increasing as fugitives from the battle made their way to join him, Gelimer decided to advance on Carthage.The decision was an easy one. The Vandals had been deprived of the majority of their bases as the natives had opted to support Belisarius. They could not afford to fight a protracted campaign as they did not have the manpower available for a war of attrition. A single, decisive confrontation was the only – probably highly desirable – option. A Vandal victory would cause many cities to change allegiance, and if the victory was overwhelming the invasion could be ended in one day.
Accordingly, he led his army towards Carthage, intent on drawing the Byzantines out of the city. Once there, they damaged the city’s aqueduct and camped near the city. Although this allowed them to control many of the city’s rural districts, they did not attempt to begin a siege or starve the Byzantines out. Gelimer did not want to waste men, since they were fast becoming a rare resource. He wanted a battle. Once in place, he waited, expecting either the native Carthaginians to change their allegiance, or for those troops in the Byzantine army who were fellow Arians, such as the Heruls, to change sides. He was soon in negotiation with the Huns. Unhappy, because they had been hired and, without their consent, transferred to Constantinople and then Africa, they secretly agreed to join the Vandals. They believed that if the Byzantines were victorious they would leave the Huns in Africa.
Belisarius did not share Gelimer’s views on the desirability of a battle. Instead, he waited in the town until the walls had been completely restored, thus ensuring that he would always have a secure base. Realising that treachery was always going to be a possibility, he remained alert. Having caught a Carthaginian who had agreed to join the Vandals, he had him tried and then impaled. The sight of the gruesome execution appears to have had the desired effect. All moves by other Carthaginians to league with the Vandals halted.
Belisarius was likewise aware of the restless nature of the Huns. To avoid their betraying him, he gave them attention and banquets, finally tempting them to admit to their fears and to confess their agreement with Gelimer. He swore solemn oaths that once the victory was won they would be transported home with a suitable amount of booty. The Huns agreed to return to their original loyalty, whilst deciding – like the Moors – to wait and join the victor when the time came.
Once he felt secure with the loyalty of the people and the troops, Belisarius decided to oppose Gelimer in the field. It was now about three months after the landing in Africa. First, he sent out all of the cavalry and all of the bucellarii except for 500 men, together with the army standard, under the command of John the Armenian. John had orders to skirmish with the enemy if the opportunity arose, since Belisarius had recognised that the Vandals were unable to cope with skirmishing troops. He was on no account to accept a challenge to a full-scale battle.
The next morning, Belisarius followed with the remaining cavalry and the infantry. The army marched towards Tricamerum, approximately 150 stades (about 17 miles) from Carthage, where the Vandals were encamped. The Byzantine cavalry set up their own camp, leaving a large distance between themselves and the enemy.
The Battle of Tricamerum
On the following day Gelimer waited until just before midday before leading his troops out of their camp and ordering them to assume their battle formations with a small stream directly to their front. It could be that the habit of the Byzantines to take their meals at noon was well known: the Persians had similarly attempted to force the Byzantines into forming battle lines before they could eat their meal. Gelimer may have been using the same tactic of making the enemy fight on empty stomachs.
Yet there is a further reason behind his decision to attack. When assessing the numbers available, the Byzantine forces at this point look extraordinarily light. Belisarius had begun with 5,000 cavalry, not includi
ng his personal comitatus or the reinforcements led by Valerianus and Martinus which had joined the expedition at Methone. Although the Vandals had been defeated at Ad Decimum, they had nevertheless fought hard at times, inflicting casualties and so reducing the number of men available to Belisarius. It is unlikely that the army facing Gelimer was much more than 8,000 strong. The 10,000 or more infantry were yet to arrive at the battlefield.
Facing them, the Vandal army was likely to be slightly larger than the available Byzantine forces. Many men had been lost at Ad Decimum, either killed, taken prisoner, or seeking sanctuary after the battle. Their absence was more than compensated for by the arrival of Tzazon and his men from Sardinia. Taking into account the overall manpower available (see above, Chapter 5), and deducting the losses incurred, it would appear reasonable to suggest that Gelimer may have had a maximum of around 15,000 men. It is not surprising that he wished to attack before the Byzantine infantry arrived to balance the numbers.