Augustus and his successors thus broke with the Republican policy of raising naval forces for each specific need and judged a permanent navy desirable. Yet this navy faced no opposition in the Mediterranean for two centuries. And again, we are dealing with a people so generally and with some justice considered a landbound folk, but these same Romans developed the control and organs of sea power to their highest refinement in antiquity. Such puzzling facts insistently demand an explanation if we are to understand the Roman imperial navy; what reasons warranted to the emperors the very considerable annual expense of a far reaching naval establishment and did so through the centuries? Or, to strip the problem to its essentials, how and to what extent did the emperors judge that their power required command of the seas?
The bare statement that the Roman Empire rested on the Mediterranean, though correct, will not suffice to explain the navy:
It is easy to say in a general way, that the use and control of the sea is and has been a great factor in the history of the world; it is more troublesome to seek out and show its exact bearing at a particular juncture. Yet, unless this be done, the acknowledgement of general importance remains vague and unsubstantial.10
For the first emperor, Augustus, there are reasons in abundance for his attention to the sea; the history of the dying Republic and his own rise showed clearly that the master of the Mediterranean world needed firm naval command. The squadrons which could give him that control were as a matter of fact then in existence, and had existed along with standing armies for some decades; it remained only for Augustus to give order to institutions that the half-hidden needs of the political society had already crudely formed. The demands of the civil wars had furnished the base of a permanent naval establishment just as a part of his legions and auxiliaries was organized into a standing army.
But what led his successors, not moved so directly by awareness of the importance of sea power, to maintain a standing navy across the centuries of the Early Empire? The justification, in simplest terms, may seem weak to modern military experts accustomed to cost-accounting and project evaluations: the navy was inherited, like the structure of imperial government, and the Empire was a conservative system not given to radical reforms. It could afford to support a navy without serious difficulty, just as it could provide funds to a number of emperors for huge building programs in Rome and abroad; not until the chaos of the third century did rulers have to make critical financial choices. There were, moreover, a variety of recurring services the Italian squadrons could provide for their masters, ranging from the truly useful to the whimsical, even bloodthirsty.
From the modern point of view one might think first of the protection of trade, which reached its ancient height in the Early Empire.11 Roman aristocrats demanded marbles from every quarry as well as statues, sarcophagi, and other work in stone and metal; there was at Rome even a warehouse for pepper, an eastern luxury.12 The population of the city itself, the largest in the world at that time, perhaps running half a million, also needed seaborne grain, a "care" the emperor Tiberius and others stressed as being much on their minds.13 Every year a huge grain transport left Alexandria in June and returned from Puteoli and Ostia with the etesian winds in August; to facilitate its reception at the Italian end first Claudius and then Trajan created artificial harbors at Ostia where the large merchant ships could discharge their cargoes into river boats to be carried up the Tiber to Rome itself. Port installations, parenthetically, were also improved all over the Mediterranean as at Massalia and even far-off London in the late first century after Christ.14 It is, however, unlikely that the navy had any real responsibility in patrolling this vital route; sailing ships came directly from Alexandria, but galleys could not keep to the sea for more than about 200 miles before they needed to touch shore for food and water.15 The general peace of the Mediterranean, moreover, prevented any serious interference with seaborne trade.
If one seeks a monument to the imperial navy, it may be found in the disappearance of piracy from men's minds; as Strabo put it, sailors could be totally at ease in this respect.16 From Augustus on to the early third century there is not one contemporary reference to a Mediterranean pirate; imperial literature has fearful portrayals of the sailor's dangers, but a swift pirate forms no part of the recital. After Labeo, in the time of Augustus, no jurist is known to have dealt with provisions of the Rhodian sea law on the subject until the third century.17 Piracy had been eradicated from the sea lanes, a feat not repeated until the later nineteenth century after Christ. Along with the navy other factors had played their part; the peace of prosperity eliminated the buccaneering that results from disturbed political, social, or economic conditions, and the army had firmly occupied the former pirate coasts of Cilicia and Dalmatia, assisted at some points in Asia Minor and Spain by prefects of the sea coast.18 Even at the eastern end of the Black Sea there was a guard post, "very suitable for the protection of those sailing in the area," which was further improved by Arrian.19 Only in western Mauretania, where the mountains closely approach the sea-for some 200 miles along this coast there was not even a Roman road-could problems arise; the consequence was the seconding of detachments from the Syrian and Egyptian flotillas to Caesarea in Mauretania, under experienced officers who had already commanded auxiliary units in the region. Brigands, on the other hand, did operate on land, especially in mountainous districts away from the main Roman roads, which were reasonably well guarded; but at least once the classis Ravennas had to land crews to deal with troubles on the Flaminian Way.
Again, we might assume that the navy was useful in the transport of troops from frontier to frontier; for at times outbreak of hostilities with the Parthian empire on the east or the German barbarians to the north required the reenforcetnent of the threatened sector. Galleys, unfortunately, were not very commodious craft. Nero did send some troops by sea, but the men arrived so exhausted that they were of no immediate utility;20 and legionary detachments had such big baggage trains that they necessarily marched by land.21 Imperial officials and even emperors in a hurry could be transported on warships, but Titus, son of Vespasian, came to Rome in 69 on a sailing vessel; the apostle Paul and his guard also were brought thus to the capital after mishaps. Emperors did enjoy an afternoon cruise off the Tyrrhenian coast in a galley, and Nero went so far as to try to drown his mother Agrippina in a ship designed to collapse; in the end he had to order his Misene prefect to send a captain and centurion to despatch her.22
The real utility of the Mediterranean fleets in general military assistance was in swift despatch of letters and orders. During the second century detachments of the Italian squadrons were posted at Seleuceia in Syria several times, undoubtedly to facilitate communications; at the Italian end there were naval runners from Puteoli and Ostia to Rome, where both flotillas had separate barracks. Sailors also, we are incidentally informed, manipulated the awnings in the Colosseum, and Claudius had the Misene fleet plant oysters along the Campanian coast.23
At least once in the Early Empire the essential military role of the Mediterranean fleets became more visible. The last emperor descended from Augustus and Livia, Nero, lost the support of the Senate, the urban masses, and the armies by his erratic tyranny and dissolute ways of life; in 68 he had to commit suicide as rebellious troops were advancing on Rome. Civil war followed, in which ambitious field commanders vied for the purple. Vespasian, erstwhile governor of Syria, was victor both by reason of his own ability and the cooperation of the Balkan generals; but a minor, yet important factor was the support of the Italian squadrons and his control of the food supplies provided to Rome from Egypt. In his reign the navy reached its apogee. Naval prefects now held a much higher rank in the equestrian hierarchy, and both Italian squadrons received the honorary title practoria. Among the representations of victory on his coinage only one has a specific description, Victoria Navalis, in clear reference to the role of sea power in giving hirn success.24 Thereafter the Empire passed through decades of internal peace until
the end of the second century, when civil war was again to erupt.
Conditions were not always as quiet on the frontiers. In Europe Augustus had pushed Roman control to the Rhine and Danube and even beyond; here naval power had very significant military utility. Already in the German campaigns of Drusus and Tiberius, sons of Augustus' wife Livia, ships played an important role on the Rhine and gave rise to the classis Germanica; after southern Britain was conquered under Claudius a classis Britannica provided a safe link between Gesoriacum (Boulogne) and several south English ports. On the Danube there appeared eventually the classic Pannonica on its upper reaches and the classis Moesica downstream. During the reign of Nero the subject kingdom of Pontus on the north coast of Asia Minor was annexed in connection with the Armenian wars of the period, and the classis Pontica was created out of the former royal navy. The ships in these fleets were of lighter build than conventional triremes but carried out their tasks efficiently; their bases were castra structured much as army posts.25
In peacetime the galleys patrolled their rivers to ensure that barbarians came across to trade only at designated points; to keep the manpower busy sailors also made bricks for forts and in Britain worked in iron mines and on Hadrian's Wall. During military activity they were even more useful. In campaigns across the Rhine to keep the Germans divided the army often moved in parallel columns to fix the fugitive enemy; while doing so it was aided by the classis Germanica at its back, which also operated up tributary rivers and even the North Sea, as Augustus proudly boasted.26
The wars by which Trajan early in the second century conquered Dacia, the modern Romania, are graphically illustrated in the frieze on his column in Rome. The curtain rises quietly on a countryside of the Danube with the riverbank castella that the Moesian fleet linked into a chain of defense, but immediately the tale passes to a portrayal of ships laden with barrels and soldiers' packs, which are being put on shore at a town-preparation for war. This scene, recurring at intervals throughout the early part of the reliefs, marks the usefulness of the classis Moesica in the maintenance of the army, for which the Danube furnished an incomparable route.27 The galleys themselves could not transport the materials of war, and on the Column the freight ships are clearly distinguished from warships; the main service of the latter, and a sufficient one, was in so dominating the river that this supply might proceed uninterrupted. After the final victory the task of patrolling the lowlands east of the Dacian hills was entrusted to auxiliary units backed by the classis Moesica.
During the reign of the philosopher king Marcus Aurelius (161-80) signs of trouble became more evident internally and externally. The population of the Empire was beginning to shrink and was more openly divided into upper and lower classes; the prosperity of the cities was also declining, and imperial revenues were heavily stressed by the long continued wars on the northern frontiers. In 170 a barbarian tribe, the Costoboci, broke through the Danube defenses and penetrated as far as Greece; to counter this threat the classis Pontica was shifted from Trapezus to Cyzicus, where it could firmly control the Hellespont; and a prefect of extraordinary rank was for a time appointed. The Moors ventured from 171-72 onward to ravage more widely in the Mediterranean; the emperor took over direct responsibility for southern Spain and sent an imperial officer, presumably with the aid of the Misene fleet and perhaps even of the Ravennate squadron, to chase them back to their lairs. The temporary inability of imperial military and naval forces to put down rebellious subjects in the Mediterranean itself was an evil omen, but not in itself disastrous.
After the assassination of Marcus Aurelius' unworthy son Commodus in 192 civil war again broke out, as in 68-69, when generals contended for the succession. A civilian aristocrat, Didius Julianus, bought the throne by huge gifts to the praetorian guard, but his rule was short. The Ravennate fleet, despite the efforts of Didius to strengthen its loyalty, deserted to Septimius Severus, governor of Syria, as he entered Italy. Misene sailors whom Didius summoned to Rome proved as untrustworthy; the historian Dio Cassius, then in Rome, jeered at their sorry military training.28
The Mediterranean squadrons were of great value even so to Septimius Severus in his war against another claimant, Pescennius Niger. While Septimius Severus moved east by land, the navy transported part of his forces to the Balkans at Dyrrachium and then in the Aegean probably helped the crossing into Asia Minor, where Niger was crushed. Most of the navy then remained in the east to aid in the siege of Byzantium, which had declared for Niger and held out after his suicide until the winter of 195-96. One official of the Misene fleet rendered such good service that Septimius Severus took the unprecedented step of advancing him to the Senate and promoted him steadily thereafter. In Septimius Severus' last years he campaigned along the northern coasts of Britain with the classis Britannica in support.
On his death in 211 the complex geographical and administrative frame of imperial sea power still stood in its entirety. The fleets grew older decade by decade without fundamental change; ancient discipline trained anew recruits to fill the ranks of discharged veterans; the dockyards replaced worn-out vessels with new; prefect succeeded prefect in the unending, unvarying wheel of administration. Hardened tradition carried the navy on and enabled it to meet the stresses of 193; the siege of Byzantium indicated that the imperial fleets still controlled the Mediterranean. The greater upheavals to come, nonetheless, were to show that imperial appreciation of sea power had slowly diminished; the shrinking resources of the empire had to be devoted rather to desperate efforts at maintaining military strength.
During the third century every type of political and natural calamity, including a great plague, weakened the imperial structure. Pretenders to the throne rose freely, and few real emperors had reigns of any length. On the east the Sassanian dynasty, which had supplanted the ineffectual Parthians, was a far more serious threat and at times advanced as far as Asia Minor. During the first half of the third century the Italian squadrons continued to perform their usual functions in eastern campaigns. In 214 an accident sank Caracalla's galley in crossing the northern Aegean, but he was saved by an unnamed naval prefect; and as late as Gordan III (238-44) the emperor moved east by sea at least part of the way.29
On the northern frontier the barbarians, now often partly civilized by long contact with Roman traders, grouped themselves in larger units and repeatedly broke the Roman defenses. From about 254 on to 269 the Goths ravaged the eastern provinces, at first by land and then by sea; in one foray they were reported to have had 500 light vessels. Their attacks were defeated primarily on land, but naval forces of some type did meet and stop the naval threat in battles off Rhodes, Crete, and Cyprus.
The Italian fleets could have given scant assistance against the Goths, for they were fully committed in the western Mediterranean under admirals appointed ad hoc to control the shores as well. Their limited success is illuminated by the extraordinary voyage of some Franks settled in Thrace, who seized vessels and made their way through the Mediterranean and the strait of Gibraltar to return to their homeland. Everywhere piracy again became a curse to those who ventured on the seas.
Of the 10 squadrons in existence in 230 only three remained when Diocletian became emperor at Nicomedia in 284 and restored financial, military, and political order to the badly shaken Roman world. His efforts and those of his coadjutors were directed to the restoration of the frontiers and the consolidation of a system of mobile field armies, using far more cavalry than in earlier centuries. Diocletian is often compared to Augustus, but he did not devote any significant attention to the sea. Mediterranean commerce had so declined that its protection became less openly essential, and the Late Empire, as the state organized by Diocletian is known, had no funds for the unessential. Even more important, Augustus had at his disposal a navy already in existence; Diocletian succeeded to a period in which the navy had largely been destroyed. Evidence for the Italian squadrons does continue for a time, but more and more naval activity rested on temporary flotillas
recruited for the occasion, as had been the practice in late Republican times. In the duel between Constantine and Licinius in 323-24 the former had 200 warships equipped at Thessalonica and with them won the only real sea battle in the history of the Roman Empire.30 Emperors might be hailed as "masters of land and sea," but the term was only conventional 31
One provincial flotilla, the classis Britannica, did have a brief day of glory in Diocletian's time. By 285 the Franks and Saxons had begun the raids along the English Channel which continued until they became settlers and rulers in the fifth century. That, however, was not yet to be, for Diocletian quickly took steps to check this and other unrest in the west. His assistant in the area, Maximian, appointed an army officer, Carausius, to command the fleet at Gesoriacum; after initial successes Carausius revolted and claimed the title of emperor himself on the base of British allegiance. On his coins symbols of naval power such as galleys appear, and lie guarded his realm for several years until his murder by his chief aide. By this time another deputy of Diocletian, Constantius Chlorus, father of Constantine, had built a fleet and restored central authority over Britain, thus ending the only occasion during the Roman Empire when an usurper rested his rule on sea power.
Later in the century, probably about 370, an anonymous author wrote a pamphlet for the emperors of the time advising them how to save money and improve military defense by a variety of ingenious inventions. One of these was a warship propelled by oxen hitched to wheels on the side of the galley that acted like oars. "Owing to its massiveness and the machines working inside it," the vessel "joins battle with such furious strength that it easily crushes and destroys all opposing warships that come to close quarters with it."32 The possibility of naval encounters is clearly envisaged, but there were actually no more naval battles in the ancient Mediterranean; needless to say the craft was never built, and its very suggestion shows how completely organized naval strength had vanished.
The Influence of Sea Power on Ancient History Page 8