Port of Mogontiacum (Mainz)

[Jona Lendering]

The Roman port of Mogontiacum (Mainz) was (re?)founded by Julian the Apostate, while still caesar, in 355 or something like that. A port appears to have been excavated north of the modern city. Its best-known find is a column dedicated to Jupiter from the age of Nero.

Are there indications for the presence of the Classis Germaniae in Mogontiacum before 355? (In other words: Jasper!!!!)

[Praefectusclassis]

No, there are not. The Classis Germanica operated on the Rhine to the North & West of Bonn only. One reason for that is that the Rhine was difficult to navigate further up the river. Moroever, at least Legio XXII PP operated its own ships as testified by various inscriptions indicating legionaries with naval jobs.

[Flavius Promotus]

On the other hand we don't know until when LEG XXII had their own flottilla on the upper Rhine - as far as I know, there are few traces of this legion after the early 4th century. According to some estimations her remnants where wiped out at the catastrophic battle of Mursa (351 AD), or the legion was disbanded/destroyed during/after the huge attacks by the Allamanns in the early 350ies.
The Notitia Dignitatum does not tell us anything about naval units stationed at Moguntiacum - yet finds of several small but fast warships (naves lusoriae?) clearly indicate naval acitivites until probably the first years of the 5th century.

My two solidi :wink:

[Jona Lendering]

One reason for that is that the Rhine was difficult to navigate further up the river. Moroever, at least Legio XXII PP operated its own ships as testified by various inscriptions indicating legionaries with naval jobs.

I think the second argument is stronger than the first; because the Rhine must have been just as hard to navigate in the fourth century as it was in the second. Or did the Romans develop new types of ships?

According to some estimations her remnants where wiped out at the catastrophic battle of Mursa (351 AD), or the legion was disbanded/destroyed during/after the huge attacks by the Allamanns in the early 350ies.

I would not be surprised if this were true, but is there any evidence?

(I hope I do not sound too skeptical; your help is, as always, much appreciated!!)

[Praefectusclassis]

Well, perhaps then I should add that the evidence for the Classis G. is limited to the lower Rhine to the north of the Brohl-valley, south of Bonn.

[Flavius Promotus]

the Rhine must have been just as hard to navigate in the fourth century as it was in the second. Or did the Romans develop new types of ships?

The Rhine basically consists of three sections, of which two are easily navigable, and one is not.

The lower Rhine was the 'classic' zone of operation of the classis Germanica, since the current was rather low - this means warships could most likely row against the current (even more if the winds were favourable and a sail could be used).

The middle Rhine was unsuited for naval activities, and it was also not necessary to operate warships in this area. The middle Rhine flows in a narrow valley with a succession of reefs and obstacles (e.g. the 'Binger Loch'), the current is strong, AND there were no offbranches of the river and few islands where marauding Germans could hide or mass rafts and boats for a raid.
It was possible to use the middle Rhine as a waterway downstream, but rowing up the river was most likely impossible. Ships had to be towed.

Now the upper Rhine was not patrolled by the classis Germanica (at least I don't know of any evidence for this), but this was due to the fact that both banks were under Roman control until about 260 AD when the area east of the Rhine had to be abandoned.
Basically the upper Rhine is suited well for operating warships there - before the 'correction' of the river in the 19th and 20th century, it must have been a labyrinth with many small islets and dead branches - an excellent area for Germanic warbands to play hide and seek with the Roman military forces. Patrolling this landscape with ships was simply the best possibility. (and we know from Ammianus and the Mainz finds that the Romans operated small galleys on the upper Rhine).

A lot of information about the navigability of the Rhine can be found in the first chapter of:
Konen, H.C., 2000, Classis Germanica, St. Katharinen. (in German)


Now to the XXII Primigenia - nobody knows what happened to this legion. It simply disappeared. The Magnentius uprising and its horrible aftermath are simply the best explanation.

(I hope I do not sound too skeptical; your help is, as always, much appreciated!!)

Don't worry - this is a discussion board, not a place to write supposedly infallable monologues :wink:

[Jona Lendering]

the upper Rhine was not patrolled by the classis Germanica (at least I don't know of any evidence for this), but this was due to the fact that both banks were under Roman control until about 260 AD when the area east of the Rhine had to be abandoned.

I should have thought about this myself...