British grain for the Rhine army?

[Nathan Ross]

In the fourth century, the main food supply to the garrisons of the Rhine army seems to have come across the sea from Britain. Libanius, in his Oration 18, says that "In earlier time, grain was shipped from [Britain], first over the sea, then up the Rhine", until barbarians blocked the route; instead the grain was being unloaded at the Channel ports and carried on wagons across Belgica.

Ammianus Marcellinus mentions "the supply of grain usually brought over from Britain" (18, 2,3), which was restored by Julian; Julian himself (in his Letter to the Athenians) says that "a whole fleet of many ships had arrived from Britain". Zosimus too speaks of this.

This grain supply apparently triggered an economic boom in Britain itself, presumably from government contracts. But why was this?

Tacitus, in his account of the Batavian revolt, mentions convoys of supplies sent up to the Rhine from Gaul. What had happened to the fertile countryside of northern Gaul and Belgica to make it more profitable to import produce across the Channel in later centuries? Was the land really left untilled and untended? Surely somebody must have owned it - why weren't they farming it?

[Flavivs Aetivs]

Merobaudes mentions that widespread farming didn't begin again until after the revolt of 435-436, in Aremorica (Pangeyric II. Have to get the passage off JSTOR but Clover's Translation is on there). However in the context it may have been a literary device.

The Gallic Chronicle of 452 mentions that the Alans settled in Valentinois were placed there to make the vacant lands become profitable once again. (Chronica Gallica 124 [440 AD])

[Nathan Ross]

Alans settled in Valentinois were placed there to make the vacant lands become profitable once again. (Chronica Gallica 124 [440 AD])

Yes, there are several comments in the panegyrics about Frankish and other Germanic prisoners of war being settled on vacant lands in Gaul as farmers. This was a process apparently dating back to the days of Probus, or even before that. So why was the north still not producing a surplus a century later? Areas like Toxiandria were surely prime arable land.

[Crispvs]

Could it be that the plagues which had so decimated the empire's population in the mid third century AD had been particularly severe in northern Gaul? Added to that, the persistent Gothic raiding in the Danubian regions which not only impoverished the population through extortion of valuables but killed large numbers of people and destroyed many farms and estates, could have been mirrored by similar incursions in Gaul by Franks.

If we consider another historical example of destruction of farms and a farming economy, along with the deaths of large numbers both from direct violence and starvation resulting from the destruction of crops and livestock, namely the Harrying of the North by the Normans under William the Conquerer in the eleventh century, we know that it took around two centuries for the northern English economy to return to where it had been before. If northern Gaul had suffered from both widespread plague and famine due to farms being destroyed at precisely the same time that movable valuables which could have been used to buy food were being stolen by Germanic raiders, the population may have been radically reduced to a level which could provide little more than subsistence levels of food for itself. In that situation, the idea of exporting surplus grain to other parts of the empire would not have been an option.

It is also worth remembering that the plagues seem to have been at their most virulent at about the same time that the Gallic Empire declared itself, so the people of northern Gaul may have been cut off from any help which might otherwise have been available, especially given Gallienus' need to spend so much time in the Danube provinces to oversee the campaigns to rid those areas of Goths. It took Claudius, Aurelian and Probus to reunite the empire and bring it back to some stability, but by the time Claudius or Aurelian might have moved to assist them, it might already have been too late to stop long term damage to northern Gaul's ability to produce grain surpluses which could be exported.

Crispvs

[Nathan Ross]

we know that it took around two centuries for the northern English economy to return to where it had been before.

That's a useful analogy. Thanks. It also brings to mind the effects of the Black Death in 14th century Europe, and the successive plagues throughout the Hundred Years War.

I think the reason for the 'agri deserti' in northern Gaul and Belgica used to be considered in exactly that way - barbarian raids (in 257ish, and another massive wave of them in 275-6, supposedly), coupled with plague leading to the depopulation and virtual abandonment of the countryside.

There's certainly evidence for a lot of villas in the north being destroyed or abandoned in this period. But more recently it seems that academic opinion has swung away from the idea of hordes of barbarians and devastating plagues, just as it's rejected the idea of wide-ranging coastline change due to the sea levels rising.

But even if we go with the idea of plagues and barbarians, would the land still be unproductive so long afterwards, particularly if it was settled with captive labourers? There seems to have been social and military stability in the Rhine provinces after Constantius I - unlike in north Britain, I assume, or war-ravaged France of the middle ages - so why would these conditions persist?

I'm currently wondering whether the land of Toxandria and the lower Rhine hinterland might have been deliberately left as a wilderness, to deter invasions and raids from Barbaricum - the invaders would be unable to live off the land until they'd fought their way through the Roman 'defence in depth'. But could, or would, any state deliberately abandon prime farmland in that way?

[Frank]

My idea is a bit more global. I guess not so much changed about the grain from Northern Gaul hauled to the Rhine. Perhaps the volume of production dropped during the 3rd century in Gaul. But grain was also shipped via the Rhone coming from Southern Gaul and from other mediterrenean provinces. My speculation is, that this grain was replaced by british grain, after the british agriculture became more capable in the 3rd/4th century. Perhaps it was both: Gaulish production dropped and british grain was cheaper to haul than the "southern" grain.

Also after the foundation of Constantinople, Egypt mainly supplied the East, while Rome was supplied again mainly from Africa. So the romans were happy to use the british grain. Shorter transport routes and more grain for the always demanding mediterrenean cities.

[Nathan Ross]

british agriculture became more capable in the 3rd/4th century.

It seems so. I've just read a couple of books that address this subject - Edith Wightman's Gallia Belgica, and Villa Landscapes in the Roman North, edited by Nico Roymans.

Wightman says that it's not clear why British grain came to be so important to the Rhine army in later centuries. She does suggest that the growth of the imperial court at Trier from Postumus onwards may have drained resources southwards. She also points out that the sandy soil of Flanders may have become impoverished by overfarming, and makes the interesting suggestion that northern zones might have been turned to sheep farming instead - various sources (including Diocletian's prices edict) mention woollen goods from northern Gaul. The relatively slower economic development of Britain meant that, unlike Gaul, it avoided the excesses of villa-based intensive farming in the 2nd century.

Roymans's book also makes the point that a band of fertile loess soil runs across northern Belgica, exactly the route followed by the Bavay-Cologne road. Outside of this zone the farmland is poor and sandy and unsuitable to intensive cultivation. So the area available for growing grain, for example, was very limited - unsurpringly, this loess belt was heavily populated, and later heavily fortified (the string of walled towns and burgi along the route perhaps less of a 'defence in depth' against barbarian incursions and more a protection for local grain gathered into silos and transmitted to the Rhine).

[Justin I]

Roymans's book also makes the point that a band of fertile loess soil runs across northern Belgica, exactly the route followed by the Bavay-Cologne road. Outside of this zone the farmland is poor and sandy and unsuitable to intensive cultivation. So the area available for growing grain, for example, was very limited - unsurpringly, this loess belt was heavily populated, and later heavily fortified (the string of walled towns and burgi along the route perhaps less of a 'defence in depth' against barbarian incursions and more a protection for local grain gathered into silos and transmitted to the Rhine).

From a military perspective, it seems like Britain would be less vulnerable to barbarian incursion than northern Gaul. Invaders from across the Rhine could come with almost limitless manpower (e.g. Ariovistus and Chnodomar), which would leave the Rhine army's food supply in a precarious position. In Britain, raiders from north of Hadrian's wall or seaborne pirates from the continent, while no doubt problematic, would presumably be far fewer in number, more easily dealt with and less likely to inflict a crippling blow on Roman logistics. It's annoying when a warband comes seeking some quick plunder, but it's a huge problem when a king comes and settles his people in the middle of your "breadbasket" lands, as Germanic invaders had a tendency to do.
If I were a Roman commander on the Rhine, I would sleep easier at night knowing my food was stashed behind the "moat" of the English Channel.

[Nathan Ross]

my food was stashed behind the "moat" of the English Channel.

Yes, quite! Aside from the brief disturbance at the fall of Carausian regime, and some Pictish activity in the far north, Britain seems to have been spared the chaos of the 3rd and early 4th centuries. However, it would still be necessary to transport the supplies across the sea and up the lower Rhine, through some very disputed areas on the borders of Frankish territory.

This recent article makes some interesting points:

Guarded River Through No-man's Land

The argument here is that the lower Rhine limes did not fall to barbarian attack c.275, but were abandoned when the surrounding land became too marshy to support a population. Presumably the British supply ships or barges could pass freely through this depopulated frontier zone. Perhaps it was only later, when Frankish groups (and even Saxons, according to Zosimus) began moving southwards into the river area again that the supply route became problematic.

The essay also claims that a pair of large horrea discovered at Valkenburg (Praetorium Agrippinae) were apparently constructed some time after AD316, and repaired c.AD365. This, combined with the late 3rd/4th century-looking fortification of Brittenburg at the Rhine mouth, suggests some sort of partial military reoccupation of the supply corridor, at least where it met the sea, around this time. Maybe a response to barbarians trying to interdict the grain shipments? Or perhaps the larger seagoing vessels could no longer navigate the river for some reason, and this was the place where the grain was loaded onto Zwammerdam-style barges?

[Robert Vermaat]

The problem discussed here might not be so big as it may seem. Grain from Britain being shipped into Gaul might have been necessary only because of the disruption caused by Germanic infiltrations (which Julian had been rolling back). This would have caused plenty of disruptions in the countryside, with farmers fleeing and farms being burnt down, to seriously hamper the normal flow of grain to the army on the Rhine. I don't see the need for a plague or anything that could not be settled within a few years.
However - the need to settle Germanic groups in a number of areas in Northern Gaul during the 4th c. of course can point to a serious number of Gallic provincials no longer being there.

I'm not sure that, as a Roman general on the Rhine, I would want my grain to come from Britain. Transport by ship is a precarious affair, which can be delayed for weeks if the winds blow from the wrong direction, and could easily result in the loss of a harvest if met by a sudden storm.

Of course the farmers (i.e. landlords) in Britain profited from the loss of grain production in Gaul, and we see the building of grand villas in this very period.

[Urselius]

There is evidence that marginal land in Britain, especially in the hinterland of the Wash, was brought under intensive agriculture in later Imperial times. There are also theories that the Saxon Shore forts, or some of them, were intended as secure concentration points for agricultural produce, for storage before being shipped to the continent. You therefore, potentially, have a number of factors favouring British grain supplies for the Rhine armies: farmland more secure from disruption by raiding than the Rhineland, a secure series of storage facilities and the hugely greater economy of transport by water over transport by waggon overland.