The Parthian war of 114–117 and Britain apart, the only significant territorial situation that could have been different under the Early Empire was if Northern Germany had been annexed. Tiberius avoided this; but what about his heir (who unexpectedly predeceased him)? Did Germanicus’ sudden death in Syria in 19 (due to poison) damage the Empire in the long term?
Germanicus had fought a difficult war in Germania after 14 and would possibly have been too ready to remember the difficulties he had faced (not least from the troublesome North Sea tides) to launch an attack as Emperor to retake the would-be province that Varus had let slip in 9. But the memory of Northern hordes slavering for Roman blood was a potent one in the capital, having a long pedigree from the Gallic sack of 390/87 BC and the long wars with the Gauls in Northern Italy, and the sources make it clear that there was panic in Rome after the destruction of Varus’ army. Destroying this threat would have been a major propaganda bonus for any Emperor, particularly a new ruler, though Germanicus or his eldest son Nero (a rash, easily-outmanoevured challenger to Sejanus in the late 20s) would have been more vulnerable to this temptation than Tiberius’ cautious son Drusus. When Germanicus campaigned successfully east of the Rhine in 15–16, Tiberius (parsimonious, cautious or jealous?) reined him in. But as Emperor, Germanicus would have had no checks on his ambition. Had he lived to succeed Tiberius in 37, he would have been 52, little older than his brother Claudius was at his real-life accession and physically tougher. His son Nero would have been around 31.
The practicalities of the campaign were such that Rome could not spare the troops for an attack in overwhelming numbers – after the Pannonian revolt of 6–9 made concentration of troops on the Danube essential. The Varus disaster – harassment and ultimately a trap in thick forests – was such that Rome could not overwhelm the enemy through force of numbers and better weaponry without risks, and the further the legions advanced from the Rhine the greater the risks of being cut off. A piecemeal occupation by a network of forts and the creation of a series of roads across the Rhine-Elbe area to speed reinforcements were essential, meaning a systematic campaign over years rather than a ‘quick fix’ of a speedy victory followed by the enemy obligingly surrendering. A long war like Caesar’s in Gaul in the 50s BC or the British campaigns of the 40s and 50sAD would have been needed, though Germanicus had the experience of the Northern frontier that would have given him the ability to decide if this commitment was practicable.
Rome was notably desperately short of men after Varus lost his legions, with Augustus having to raise emergency forces of slaves and gladiators in the capital. The limit of troops available for any Northern war would have been similar to the three legions (plus temporary detachments from others) sent to Britain in 43. Conquered territory taken from the fierce tribes would need to be held down by force for years, with the mixture of forests, mountains, and marshes meaning that even the task of building Roman roads to connect forts would be slow and expensive. It is noticeable that, in a comparable situation, even 120 years after Caesar’s conquest of Gaul parts of the North-Eastern tribes (nearest to potential allies across the Rhine as well as less urbanised) were willing to revolt and join Civilis’ Batavians in 69–70. The Germans would have been equally resistant and in need of longterm garrisons, with their tribal allies across the new frontier (the Elbe?) willing to aid them. The terrain of forests and swamps was conducive to a guerrilla war, though no more so than the Ardennes which Rome had held since Caesar’s time.
If a glory-seeking Emperor had been willing to reverse the ‘disgrace’ of 9, he would have had to raise new legions for a long-term occupation, though the late Republic had been able to sustain a far larger army until Augustus demobilised it and five or so legions could have been sustainable. The political danger of putting such a large force in the hands of one general would have been a drawback, as he would have had to be carefully selected. The new governor (of ‘Germania Ulterior’?) would have had the potential to take advantage of weakness in Rome as Vitellius did from the Rhine and Vespasian from the Jewish war in 69. Ideally, even if one general – preferably an Imperial male – was in charge of the annexation the subsequent province would need to be divided to reduce the number of legions available to a potential rebel. Alternatively, the troop-deployment East of the Rhine could be numerically matched by the force available to the governors of Lower and Upper Germany. That should dissuade the new governor from revolting in the event of a disputed succession in Rome.
The conquest of Germany: useful long-term consequences?
If Varus had defeated Arminius’ coalition in 9 problems would not have arisen to that extent, and the Empire would have avoided the shock of defeat. A better general than Varus would not have allowed himself to be led into a German trap far from the Rhine by supposedly loyal German ‘scouts’, or if he had done so he could have provided more inspiring leadership. A dogged defence of a strong position against wave after wave of Germans was capable of holding the lightly-armed tribesmen at bay until they became exhausted, even in heavy rain. The Romans had large shields, cuirasses, arm- and leg-guards, and a variety of swords and javelins plus some archers; they also had a tradition of discipline and fought in defensive squares. The Germans were lightly-armed and relied on the effect of a terrifying charge, plus individual combat. They were intimidating in the charge, but no good in a long pitched battle; the Romans would have had the advantage if they could hold out for several hours.
The prospect of a charge by thousands of savage Germanic warriors was not unusual to Roman soldiers, though it was always feared. Being outnumbered could be handled by a competent Roman general, as could unfamiliar territory. Marius, six times consul in succeeding years and Rome’s greatest commander around 100BC, had managed to win defensive battles against the equally intimidating Cimbri and Teutones when Roman legions had to tackle comparably daunting hordes. Once the enemy was forced to draw off, at worst the Roman general could have managed to withdraw slowly to the Rhine with his troops marching in fightingformation and reducing the numbers of stragglers who could be isolated and killed. It would be more difficult to win through back to the Rhine if their scouts deserted, as Varus’ did, but not impossible. The army would have been available for future punitive strikes – probably led by Germanicus around 12 – once they had received reinforcements and the temporary coalition of Germanic tribes had broke up, and would not have suffered the trauma of defeat.
But the forests, swamps, and mountains of North-West Germany were more difficult to penetrate and then hold down by a chain of forts than was equally truculent Gaul after Vercingetorix’s defeat. The barren heathlands and thick forests did not give promise of a future of self-sustaining agricultural settlements and growing towns filled with ambitious Roman traders, at least for decades. The archaeological remains indicate a poorer culture of Germanic villages than in Gaul or ‘Celtic’ Britain – and even less wealth East of the Elbe. There would have been the danger of another transtribal leader arising, and the state of military morale in Augustus’ later years and the ease with which mutinies commenced in 14 shows that the morale of the underpaid, overworked frontier troops was low at this crucial point. The situation in 14 shows that Varus’ victory would not have solved Rome’s German problem – indeed, it could have posed a new threat by reassuring Augustus that the German tribes were not that great a threat. Augustus had been using as few troops as he could get away with ever since demobilising the Triumviral armies in the 30s BC, with around thirty not fifty legions, and sought a German victory on the cheap. Varus could have defeated the tribal coalition, ravaged their villages, destroyed stocks of food, and driven the surviving warriors into hiding in the forests – reassuring Augustus that the Germans were manageable. He could then have imposed a temporary submission in 9 or 10, Augustus installed a smaller garrison than was really needed, and an outbreak of mutiny in 14 inspired the Germans to revolt. The conditions for troops in frontier-forts in the German forests would have been as bad a they were on the lower Rhine, causing grumbling veterans who had had to serve longer than their promised time in service to decide that Augustus’ death gave them an opportunity to insist that they were discharged. The mutiny of 14 would have occurred on the Elbe in that case, and probably led to evacuation of the new province.
The permanent acquisition of a new province up to the Elbe would have required a major effort over several decades before the danger of revolt abated, and still not have provided much in the way of local revenue. Timber for the fleet was the only obvious local resource. But if the frontier had been adequately defended and the local Germans not taken advantage of a change of Emperor to revolt, the impressment of tribesmen into the army would have added to Roman military manpower and denied it to potential opponents. The danger from the Rhine frontier became acute during the civil war of 69 due to the departure of many troops for Rome under Vitellius, the poor state of the remaining army, and inspiring and coordinating local rebel leadership under Civilis, but thereafter there was only one major war against the Rhineland tribes until the early third century: the campaigns under Domitian in the 80s. These tribes would have been part of the Empire and their menfolk enrolled in the legions so they would not have been a threat had Rome secured the Elbe frontier in 9 or the late 30s/40sAD, though the tribes beyond the Elbe could still have challenged the Empire at this point (e.g. if there had been a local Roman rebellion equivalent to that of Saturninus at Cologne in 88).
The concentration of legions in the new province would have provided a tempting force for ambitious generals to use against the Emperor, and in that case Vitellius could have been in charge of the troops – on the Elbe rather than the Lower Rhine – and revolted in 69. Would his departure have led to German revolt? But if Rome had come through 69–70 still holding the Elbe, it should have provided a hiatus of military activity until the 200s for Romanisation to develop and the German province to become as fully secure as Belgica and Civilis’ Batavian island were after 70. In that case, Rome would have had to face a smaller challenge from the local Germans in the third century and would have had many of the tribes facing the Rhine (including the Franks and Alemanni?) incorporated in the Empire and added to its legions. Indeed, if the conquest of the Marcomanni in Bohemia by Marcus Aurelius in the late 170s had been followed through (see below) Rome could have been defending a frontier from the Elbe to the Carpathians rather than from the Rhine to the Danube. The Empire would have had fewer opponents, though the tribes beyond the Elbe would still have been pressing against the frontier, and correspondingly less of a distraction from the wars on the lower Danube from the 230s.
The extra, Germanic, manpower available for these wars would have been invaluable besides enabling the Emperors and local generals to campaign more on the lower Danube and less on the Rhine. There would have been no need for Domitian’s distracting Chatti wars in the 80s – though he could have attacked other Germans to gain much-needed (in his mind) glory. Holding ‘Marcomannia’ as far as the Northern mountains of Bohemia too would have provided Rome with a more easily-defensible frontier in the North, with the enemy only able to use the gaps in the mountains – the Elbe valley, the Moravian Beskids, to either side of the Tatra, and Ruthenia – to invade the Empire. Thus there would not have been the need for huge garrisons on the upper Rhine or upper Danube, and more troops could have defended the Elbe and the gaps in the chain of Carpathian ranges. In this case, it is less likely that the Empire would have lost crucial battles such as Abrittus against the Goths in 251 – at least on account of troop-numbers, if not incompetence. The avoidance of the raids into the Empire and political ‘break-up’ of the Roman state in the 250s would have been momentous, though it should be remembered that Rome would still have lost manpower in the plague from 252. Incompetent leadership and/or the bad luck of a civil war were crucial factors that better frontiers would not have affected. There was also, of course, the perennial possibility of conquest in the Augustan/Julio-Claudian period followed by a ‘pull-back’ after 69 to save on men and money.