Arthur's dykes

[Erpingham]

Incidentally, I completely disagree with anyone who underestimates the achievements of Roman engineering or the learning that went behind it. 

I didn't mean to give the impression that I underestimated Roman engineering.  Water engineering, moving water over huge distances with precisely surveyed gradients, never ceases to amaze. 

[aligern]

I suggest that before we decided that the engineers were Roman or non Roman we would have to look at the works of those dykes of similar age in Europe and those tgat occur in known non Roman situations.  There are certain commonalities in such earthworks tgat are caused by tge materials...walls too steep fall in, too shallow and they offer weak protection.  If the dyke is tge result of removal of material that then forms  a ditch then there will be a relationship between the two. It may indeed be that all military engineering from the Elbe to the Rhine/Danube in the period from AD 0 to AD 900 is effectively Roman military engineering.  Whilst I wouldn't accuse the Germans of building stone fortifications or major bridges or suspended roads or basilicas or tempkes, dykes are a bit simpler..  If Germans serve in the Roman army they acquire the techniques of field fortifications. As we do not gave Roman engineering manuals we have to assume that the techniques are passed verbally and by practical experience. It is wrong to think of a Roman in the fifth century with a German workforce. The lead engineer was probably borne German, his gang leaders are Romano Germans  and his troops Germans who joined the Roman army or whose  fathers or grandfathers joined and who kept homes, even familues beyond the Rhine.
Roy

[Imperial Dave]

thanks Roy, that was the point I was trying to make (badly). I agree the dykes are formulaic (Roman) and merely suggest that since Germanics were part of the Roman military for 350 years by the time of the post Roman British period, that there is no reason to suppose that the engineers were not ethnically 'German'

[Jim Webster]

When you stop and look at the various banks and dykes in the UK, according to the excavation report, Maiden Castle in Dorset had at least one of its banks faced with limestone
Maiden Castle in Cheshire "Radiocarbon dating indicates that the ramparts defending Maiden Castle were built in around 600 BC.[7][9] Built from earth and timber, the inner rampart was originally 20 ft (6.1 m) wide, with a revetment of dry stone walling behind the bank, and at least 10 ft (3.0 m) high. The outer bank was originally 25 ft (7.6 m) wide and about 10 ft (3.0 m) high. It was built from sand and had a dry stone facing at the front and no revetment behind. The outer bank was later enlarged: the outer face was extended 8 to 10 ft (2.4 to 3.0 m) away from the fort and the revetment moved. Its height was probably increased to 12 ft (3.7 m)." (from the wiki)

So the level of engineering necessary to build these post Roman dikes didn't rely on remembering Roman technology.

Indeed it might well be that the constructions of pre-Roman Britain were more complex and better engineered that post-Roman Britain
People might find
https://www.academia.edu/1891255/Grims_Ditch_Wansdyke_and_the_Ancient_Highways_of_England_linear_monuments_and_political_control

Interesting

[aligern]

One could mischievously learn from Storr's  calculations  that whoever designed the dykes used their feet to measure the lengths. What i did not see in his calculations is a consistent set of ratios. So for a dyke x feet high dig a ditch y feet wide and z feet deep  pile the spoil .
The correlation of dimensions with a Roman foot is unsurprising if a literal foot is the  unit of measurement.

[Imperial Dave]

regardless of whether certain dykes were built by Germanics or Britons it does tend to suggest areas or polities in existence throughout the Late and post Roman time period. I would really love to see further evidence from these dykes to establish more accurately the timeframe of building and use. One thing I did think that the book could have provided was an overall view of all the dykes in their entirety. Storr provides mapping for isolated areas but not an overall view of the SE which I think would have helped to visualise and discern any patterns better

[Anton]

The British civates arise out of tribal territories minus imperial confiscations and any land taken by the Roman army for military installations and their support.  We should be able to take one, say the Cantii, and look at Storr's dykes there.

I think the British polities were there in the Late Roman period as is evidenced by Marwanad Cunedda.

[Imperial Dave]

Yes. I think that would be doable Stephen. An enjoyable task if/when time is available 

[Erpingham]

Just checking but does Storr say all the dykes were built by Roman-British?  Justin implies he believes the earliest were by Roman-trained engineers, presumably in the pay of Roman-British polities, but does he allow any to the Germanic incomers?

[Justin Swanton]

Just checking but does Storr say all the dykes were built by Roman-British?  Justin implies he believes the earliest were by Roman-trained engineers, presumably in the pay of Roman-British polities, but does he allow any to the Germanic incomers?

According to Storr the earliest dykes were built by the Jutes in Kent to keep the Romano-British out (they face towards London), and they were built with the same technical precision as later dykes constructed by the Romano-British themselves. Which raises the question of who did the Jutes find/bribe/blackmail to oversee the construction of their dykes? There are dykes built by the Saxons and Northumbrians and used in a bite and hold strategy. If I get the time I'll draw up a map of England showing all the dykes, their facing and their precision of construction. If.

[Anton]

Yes, it's the time Dave.  I've a big, out of our period, research project ongoing.

Just as an aside if Koch is right about an early chronology for St. Patrick then we can read the letter to the soldiers of Coroticus in a new light.

Justin, I think that would be incredibly useful should you find the time.

Another thing, we might heed Gildas and his ongoing civil wars among the British and we can note inter Germanic fights.  Maybe some of our British dykes are intended to contain other Britons and some German ones other Germans.  That means Justin's proposed project would be even more useful in understanding the period.

[Jim Webster]

If I get the time I'll draw up a map of England showing all the dykes, their facing and their precision of construction. If.

Just to second Anton, that would be very useful

[Imperial Dave]

If I get the time I'll draw up a map of England showing all the dykes, their facing and their precision of construction. If.

Just to second Anton, that would be very useful

thirded!!!

[Patrick Waterson]

Might I provide one thought: if an ongoing trend of dyking off bits of country is interrupted by a general reconquest in which the Britons reclaim pretty much the entire island for, say, 30-40 years, how shall we know?

[Anton]

It's a good point Patrick.  I think we will just have to divine what we can against what we think we know.

I had a look at my copy of Storr last night.  Thought I'd look at the south coast stuff.  Five minutes in and Jim is telling us the word 'cam' means river when it actually means crooked.  His grasp of history and linguistics take him all over the place to no avail. But, the dykes seem solid enough and that makes this exercise worthwhile.