Antonine Itinerary XIV 5): Venta Silurum to Abone

This section near the beginning of the Iter presents several problems (which is the reason that it’s been left until last). Venta Silurum is Caerwent, Aquae Solis is Bath; in between are the two stations Abone  and Traiectus.

The text of Iter XIV from the 1848 edition of Parthey and Pinder: ‘Also another journey from Isca to Calleva’ – the first being via Gloucester.

Looking at the other stages on this Iter, it seems that the Itinerary‘s distances are fairly accurate, especially on the shorter stages and where the route of a Roman road is clear or can be conjectured.

Both Venta and Aquae Solis were Roman towns. Their identification with Caerwent and Bath is certain, the distance between the two being 14 + 9 + 6: 29 mpm or approximately 43 km. But where would the Severn Estuary have been crossed (and why does the Itinerary make no mention of a crossing which would have been at least a mile by ferry)?

Theoretically, the crossing could be made in three places: the shortest would be the ‘Old Passage’ between Beachley and Aust, about 1.7 km (how did they measure a sea or river crossing in paces?). The drawback here is that the Itinerary gives the distance between Venta Silurum and Abone as 14 mpm (about 21 km). But if Abone is Sea Mills, the distance via Aust – even as the crow flies – would be nearer 27 km, which suggests an actual road (and ferry) route of nearer 30 kms.

The second possible crossing would be the ‘New Passage’: from Caerwent it  is a mere 5 km down to Sudbrook on the estuary (where there was a Roman camp), and a 3 km crossing to Redwick. It would be, as the crow flies , about 21 km in total to Sea Mills, which makes the whole distance to Bath about 43 kms. Exact, though the road route down from Redwick to Sea Mills is not clear. And good luck to the ferryman because that entailed crossing by the treacherous narrow channel known as The Shoots, thus described:

“Sailing through The Shoots in the days before powerful engines was especially dangerous, and called for very high level of seamanship. The area is fringed by rocks on each side of the river and known for tricky whirlpools.”

The third possibility would have been a considerably longer crossing from Sudbrook, straight to the mouth of the Avon, and then upriver directly to land at the port at Sea Mills, portus Abonae. That would also be about 43-44 kms to Bath and there is a certain logic to arriving at a port by boat. Evidence of an important port has recently been found at Caerleon (Isca Silurum), where Iter XIV started. From Caerleon where would boats  sail to?

Blue: Beachley to Aust; green, Sudbrook to Redwick; pink, Sudbrook to Avonmouth

There appears to be no incontrovertible evidence that Sea Mills was Abone/Abona/Abonae, other than that there was a Roman settlement there, on the Avon, dating from a very early period; and the identification seems to have been accepted as a given. So we have arrived at Portus Abonae.

The extent of the Roman port of Abonae at the confluence of the rivers Avon and Trym


Antonine Itinerary XIV 4): Cunetio to Calleva, via Spinae

Doubts are sometimes expressed as to the location of Spinae, the penultimate station of Iter XIV. Is it Speen, Berkshire, on the outskirts of Newbury, Spone in Domesday?

Domesday entry for Speen,Berkshire

The Nottingham toponymists consider the origin of the name to be unclear, ‘possibly, ‘wood-chip place’, from spōn (Old English), a chip, a shaving of wood; perhaps also a wooden shingle tile’. They make no mention of Spinae which in Latin would mean thorns, not woodchips.

There may also have been lingering doubts on account of the fact that no Roman settlement has been discovered at Speen, unlike at Isca, Venta, Aquae Solis, Verlucio, Cunetio – and the final station, Calleva (Silchester), main centre of the Atrebates.

Calleva Atrebatum: the east-west road leads on to Speen, Cunetio, Corinium and Glevum

The earliest recorded name for Speen seems to be Spene, perhaps of the 9th century; though intriguingly, the twelfth and thirteen centuries yield Spenes, Spienes and Spenis which look like plural forms, as is Spinae. Faute de mieux, the identification stands. In any case, it is not here so much a matter of identifying Spinae as on checking how accurate the Itinerary is overall in its measured distances.

Do the distances correspond with those given by the Itinerary? Spinae was supposedly midway beween Cunetio and Calleva, xv mpm, or 22.2 km from both; so Cunetio to Calleva is therefore roughly 44.4 kms: how accurate are the Itinerary‘s distances? The conjectural (another variable) road from Cunetio-Spinae-Calleva is, indeed, about 44.5 kms.

However, the two sections are not quite equal: Cunetio to Speen, following Margary 53, is nearer 25 km, whereas Speen to Calleva is barely 20 km.

Thatcham, a little further on from Speen on the main road, has also been suggested as being Spinae. There was seemingly a small Roman settlement there – and even now a ‘Roman Way’. However accepting that suggestion would increase the Itinerary‘s discrepancy, adding about 5km to Cunetio to Speen/Thatcham, making it about 29km; and removing  5km from Thatcham/Speen  to Calleva, making that about 15km. That looks out of keeping with the general accuracy of the Itinerary.

The individual sections so far considered (note, the distances Venta-Abone-Traiectus-Aquae Solis have so far been omitted for later consideration) are recorded in the Antonine Itinerary as totalling 109.52km, while the conjectural road route would be 106 km. That is impressively close. Only one stage (Verlucio to Cunetio) falls significantly short of the Itinerary‘s distance, and is the main reason for the overall discrepancy. Strange, since the route from Verlucio to Cunetio seems very ‘straight forward’ and therefore could have been expected to be very accurate:

The route corresponding closely with Margary 53. Click to enlarge.

These results suggest the Itinerary was accurate, discounting the many imponderables and small compensating discrepancies, to within a very few kilometres. So, to the final puzzle: what of Abonae and Traiectus?

Antonine Itinerary XIV: 3) Verlucio to Cunetio

This stage is the longest one on Iter XIV – xx mpm – and therefore the one to test any theories about the accuracy of the Itinerary‘s distances most severely. Like the two stages just previously considered, the stations where this stage begins and ends have been pretty firmly identified,  Verlucio as Sandy Lane in Wiltshire, which stands on the site of the Roman road designated Margary 53; at the other end, Cunetio stood just south of Mildenhall (My-null), near Marlborough.

Time Team artist’s impression of the Cunetio mansio

If you can bear the Time Team banter, their episode on the archaeology of Cunetio is here and is interesting because they identified a 2nd-century mansio. Mansiones were travellers’ ‘coaching inns’, in settlements near the main roads, where there would be food and accommodation, and where horses could be changed – an additional sidelight on the Itinerary‘s Cunetio.

The archaeologists speculated that Cunetio might have been a Roman tax collection centre (perhaps explaining the huge hoard of 55,000 Roman coins found there); and perhaps a market town, where agricultural produce from the area would be brought in to be sold.

The site is alongside the River Kennet which presumably gave its name to the Roman town. A 10th-century source names the villages of East and West Kennet, just under 10 miles down river, as Cynetan.

Early Ordnance Survey maps trace the Roman road from just outside Bath through to Sandy Lane (Verlucio), then passing  south of Beckhampton and on to Silbury Hill where a Roman village was discovered in 2007. The track is lost here, though it points to a route straight through Marlborough on a line which which would lead directly to the site of Cunetio, still roughly corresponding to Margary road 53.

The site of Verlucio lies just at the point where there is the slight dip southerly at Chittoe, so the route from Verlucio to Cunetio is as clear as it can be, visible or guessable, the road distance measuring c.24.8km. It is as near direct, Roman road style, as it could be, so as the crow flies it is a similar distance, 24km.

OS map: the site of Verlucio, close to the Roman road

However, the 20 mpm of the Antonine Itinerary would be 29.6 km so there is some discrepancy there. Either it was measured inaccurately, or the manuscript tradition could be corrupt, recording xx mpm for xv mpm (22.2km) for example.

Antonine Itinerary XIV: 2) Aquae Solis to Verlucio

This section of the iter is one of the most straightforward: signs of a Roman road are distinguishable at least from Bathford, just east of Bath. This is the Margary road 53 which carries on to Verlucio/Sandy Lane and beyond in an almost straight line. As a result, the ‘as the crow flies’ distance is virtually the same as the road route. From the satellite view the line of the road can be made out by the stright line forming the division between the fields.

Red dots are just below the route of Margary road 53, indicated by the field boundaries. Click to enlarge.

As on Margary 53, the road seems to dip southwards near the supposed site of Verlucio, and then continues east to Cunetio. The ‘as the crow flies’ distance between Aquae Solis and Verlucio is 22.43 km, as against the possible road route from the very centre of Bath, which would be about 23 km. The Itinerary‘s  15 x 1.48 = 22.2 km is close.

Like Caerleon to Caerwent, where there is a predicted,  direct Roman road, the Itinerary is fairly accurate; on this stage very accurate.

And so to the stage between Sandy Lane/Verlucio and Mildenhall/Cunetio …




Antonine Itinerary, Iter XIV: 1) Isca Silurum to Venta Silurum

For the calculations in kilometres and modern miles in what follows, the equivalents used are the commonly accepted 1,000 Roman paces = 1.48 km or 0.92 modern miles. The edition of Itinerarium Antonini Augusti consulted is that of G.Parthey and M.Pinder, Berlin, 1848. Iter XIV is on p. 233.

How accurate the Itinerary’s distances ever were, and whether/where the manuscript tradition might – perhaps – be corrupt, are problems to acknowledge rather than linger over at this stage. Iter XIV, on which Traiectus lies, starts at Caerleon (Isca Silurum) and ends at Silchester (Calleva Atrebatum), and is an alternative route (alio itinere) to the one via Gloucester. The total distance is recorded as CIII (103,000 paces or 103 Roman miles); and the separate distances given between each stopping point, satisfyingly, add up to exactly CIII. So far, so good.

The first stage of the iter, Isca Silurum (Caerleon) to Venta Silurum (Caerwent),  is given as VIIII mpm or 9,000 paces – c. 13.32 km or 8.28 miles. As the crow flies, the distance between the two is 13.23 km or 8.22 miles. Is that what the Itinerary’s measurements mean, or is it just a coincidence? A coincidence, surely, since mille passus must refer to a distance walked (rather than flown), mustn’t it? [But see future blog on this.] The ‘predicted’ Roman road route between Isca and Venta is roughly along the A48, though little archaeological evidence seems to exist.¹ Following that route (and cutting out some of the wiggles), the distance would be at least 14.42 km or 8.96 miles.

Measured distances: Top, along the A48, bottom, as the crow flies. Click on image for clearer view

There are reasons to think that the measurement of this stage, at least, of the journey ought to be fairly accurate. Firstly, the terrain is easy: along a flattish coastal plain, gently undulating but with no deep valleys, wide rivers, mountains or steep hills to negotiate. It’s therefore not too surprising that the as-the-crow-flies distance is almost exactly as recorded by the Itinerary. Secondly, at 9,000 paces it is one of the shorter stretches between stopping points on this iter (the shortest is 6,000 paces, the longest 20,000). Longer stretches can present more possible deviations and uncertainties; and there are always the unknowable variables introduced by the marching army or whoever measured the distances used by the Itinerary.

The A48 road just past the turning left to Parc Seymour, travelling east.

We can infer that the Itinerary was very accurate in its measurement here if:

a) it was measuring the ‘as the crow flies’ distance or

b) 1,000 paces represented c. 1.6 km/0.99 miles, instead of the commonly accepted 1.48m/0.92 miles. These revised equivalents can be used for calculating the other stages.

Not very much more can be learned from this stretch: there are certainties and uncertainties. Old Somerset, not for the first time, has wandered off the beaten track; but Traiectus may bring us back a little closer to home.

¹ “West of Crick, the road is assumed to follow the route of the modern A48 through Caerwent, though the section between Crick and Cat’s Ash is almost all purely conjectural, except where it passes through Caerwent where it is confirmed by the position of the gates. Although [the] modern A48 consists of a series of straight alignments, these may owe their origin at least in part to turnpiking. To the west of Penhow Castle, Ordnance Survey fieldworkers excavated a short section of agger but little further information was recorded about the results of the excavation”, Roman roads in Southeast Wales. Desk-based assessment, p. 17, report for Cadw by A. Sherman and E. Evans, Sept 2004.