Classis Germanica

The fleet was assembled in 13 BC, and was responsible for monitoring the entire Rhine from the confluence of the Vinxtbach and its navigable tributaries as well as the Zuiderzee and North Sea coastlines in the Rhine–Meuse–Scheldt delta.

Later on, the estuaries on the right bank of the Rhine were also included in its charter in order to maintain a smooth flow of transportation and commerce on the river.

[1] Besides specifying the local auxiliary troops involved, it also lists the Rhine fleet, that likely was still in existence (in altered form) until the 4th century.

[3] The advance of Tiberius at the Elbe (Albis) in 5 AD was accomplished by means of a combined land and sea operation.

One year later under the command of legate Silius, Anteius and Caecina a fleet of a thousand ships were sent to dock at Kiel.

The fleet included special innovations such as landing craft with flat bottoms and rudders at the stern and bow, ballista transporters, wide arks for cavalry horses, bridge material and food and gear.

The Rhine fleet brought an expeditionary force in the revolting area, including to the besieged Roman port facility Flevum (Velsen).

During the Roman civil war (Year of the Four Emperors) in 68/69 AD, a riot among the allied Batavians under Julius Civilis spread to almost all other Germanic tribes along the Rhine.

[8] The supreme commander of the army of the Rhine, Quintus Petillius Cerialis, was transported by the fleet of Classis Britannica with the Legio XIV Gemina and invaded the rebels on land.

At the mouth of the Meuse (Mosa), the numerically inferior but better trained Classis Germanica fought the Batavian fleet in a brief skirmish.

After the end of the so-called Gallic Empire under Postumus and after numerous heavy incursions by the Franks, the Classis Germanica collapsed in the last third of the 3rd century.

Roman river warships were mentioned on the Rhine for the first time in 280 again, when Germanic invaders succeeded in setting several of the new navis lusoriae on fire.

[15] In the winter of 357/358 Julian's troops joined a large group of Frankish marauders on the island in the Meuse (Dutch: Maas).

Constantly patrolling, Lusorien prevented the permanent formation of a solid sheet of ice, so that the Franks were unable to escape across the river and had to finally surrender to the Romans after two months of siege.

After their honorable discharge (honesta missio) they were provided with either money or land and were also usually granted citizenship if they were free subjects of the Empire (peregrini).

The types of vessels that made up the Rhine fleet consisted of freighters (navis actuaria), rafts, transports as well as some heavy warships.

The main role of the fleet was to ensure freedom of navigation along the Rhine, Scheldt and Meuse rivers and their tributaries, and continuing on up the coastline to Zuiderzee and the North Sea.

With the end of plans to conquer the right bank of Germania Magna under Tiberius, the Romans altered the role of the Classis Germanica to deal chiefly with daily patrols on the Rhine, and operations along the North Sea Coast dwindled in importance.

The fleet was mostly concerned now with the extraction and transportation of building materials, since the freight cost by water were much lower than by land (approximately 1/6 of road tariffs),[22] although they continued to provide a river patrol service.

By giving up the doctrine of central massing of the fleet and their distribution to smaller castles and burgi, numerous units were concentrated at focal points of the border in case of need within a few hours.

This was best achieved with the smaller and more mobile navis lusoria, with which one could also deal with potential intruders either right on the Rhine or in amphibious operations, together with land forces.

[24] With effective communication, it was possible for the High Command to bring at least four patrol boats to vulnerable locations in this time and so at the beginning of the battle up to 100 naval detachments (milites liburnarii) could be deployed.

Due to the flat bottom construction of the Roman lusoria it was also possible, during an armed reconnaissance mission for example, to venture into Barbaricum waters.

Another protection were the then widely ramified, sometimes almost impenetrable and marshy floodplain of the Upper Rhine[25] and the presence of numerous meandering tributaries, which also considerably more difficult to approach the border zone.

[26] Furthermore, in a fight the Germanic tribes on the Rhine couldn't muster anything remotely equivalent to the Romans' highly developed river-going battleships.

Had the invaders somehow managed to overcome all these difficulties, there was still the possibility that they could be intercepted at the very last moment back on the Rhine again on the return trip from one of their marauding attacks, and have all their booty confiscated, just to see it redistributed among the border soldiers who had taken part in the battle (see also Hortfund von Neupotz [de]).

The headquarters of the Classis Germanica was originally located in Castra Vetera (in Xanten), later in the Alteburg naval fort [de] about 1,5 km south of ancient Cologne.

It is believed that the late antiquity (left bank) fortifications between Bingen and Bonn were built during the reign of Constantine I's sons (ca.