La voie de l'Itinéraire d’Antonin d’Aginnum (Agen) à Lugdunum (Saint-Bertrand-de-Comminges)
Authors: Colleoni Fabien , Petit-Aupert Catherine 
Published: April 2023

Although some parts of Gaul have given rise to research programmes leading to the reconstruction of an extremely tight-knit Roman road network, it has to be acknowledged that this was not true of the cities of central Gascony in Antiquity. Even if many notable routes have been proposed in earlier works, only the major roads connecting the main cities of the civitates are concerned here, which are the only ones documented, even partially, by the itinerary sources and by archaeology. One such road, linking from north to south Aginnum (Agen) and Lugdunum (Saint-Bertrand-de Comminges), referred to in the Antonine Itinerary has prompted sporadic research summarized here around the course of the road and the sites bordering it in the civitates of Auch and Lectoure.
THE COURSE OF THE ROAD FROM AUCH TO SAINT-BERTRAND-DE-COMMINGES.
Although the course of the Auch (Elimberrum)/Saint-Bertrand-de-Comminges (Lugdunum) road has given rise to many reconstructions based essentially on topographic and toponymic appraisals, the discovery of the Constantinian milestone of Castelnau-Magnoac and the consideration of archaeological data in identifying the road station of Belsino have contributed to the advancement of knowledge of this line of communication (fig. 1). While no station is shown in the Antonine Itinerary between Auch and Agen, the Belsino station lay on the Auch/Saint-Bertrand-de-Comminges road. Among the localities suggested, only that of the sites of Les Tuileries at Samaran is worth any toponymic and archaeological consideration. The name Belsino, of Iberian origin, gave Boussens in French, derived from the medieval forms Belsen and Bolsen attested in the twelfth-century cartulary of Berdoues on the location of the Les Tuilieries site. Archaeologically, mention is made as from the nineteenth century of the remains of a roadway with a “paved” surface. Above all, a recent field-walking survey has confirmed the existence of a large site, probably an agglomeration of sorts occupied from the end of the Iron Age until late Antiquity. The proximity of the site of Les Tuileries and the Castelnau-Magnoac milestone, just 4 km apart, and located in a similar topographical position, that is, on the upper part of the slope along the left bank of the River Gers, lends support to the idea of the roadway running along the western heights of the Gers valley. However, the exact course of the road cannot be reconstructed and so mapped for want of archaeological evidence of the roadway. However, data from the archaeological maps make the hypotheses likely : apart from the site of Les Tuileries, three other sites lie along this route or not far off it. In particular, the road serves or skirts sites occupied in the late Iron Age. Accordingly, the line along the hill crest must have formed a native trackway that could have served as a basis for the road of the imperial period.
THE COURSE OF THE ROAD FROM AUCH TO LECTOURE.
The first source that we can reasonably attribute to the Auch-Lectoure road segment (fig. 3), the Crastes milestone, it too from the time of Constantine, was not found on the supposed course of the road. Serving as a stand for the font in the church at Mons, the mile-marker is some 6 km from the route. Its weight suggests it was moved over only a short distance, leading it to be associated with the route of the Itinerary. Researchers in the Gers have contemplated two routes to reconstruct the course of the ancient roadway, one up and down the hill slopes of the left bank of the River Gers, the other across the floodplain on its right bank. Archaeological discoveries from excavations and aerial surveys in recent decades have come out in favour of the second hypothesis. The roadway has been unearthed on the right bank of the Gers, some 6 km north of the capital of the Auscii, at Endoumingue (Auch). The 8 m-wide road surface, made up of small pebbles, was set upon a 1 m-thick backfill of alluvium. The objects found indicate it came into use in Augustan times. Further north, the road may well have run beside the grave exhumed at Lamothe that probably dated from Late Antiquity. The deceased was in a lead sarcophagus. Among the grave goods, a lead mirror frame decorated with representation of a procession of Dionysus was an exceptional item. A recent study suggests this object had been manufactured in a workshop near the legionary camp at Carnuntum, giving us to imagine the grave’s occupant had spent time in the military on the banks of the Danube. The soldier buried at Lamothe may have stayed shortly before his demise in the probable hostelry of La Goudagne, some 400 m further north. This site, which has been clearly depicted by aerial photography (figs 4 and 5) corresponds to a huge complex whose elaborate architectural layout evokes a road station comparable to a praetorium, a state hostelry reserved for provincial senior officials. On the edge of this large establishment, the aerial survey also detected a straightline trace (fig. 6) identified as the Roman road. Where the road intersects a side road leading to the main building of La Goudagne, a small four-sided building, detected by aerial survey, remains difficult to interpret but it might be a funerary monument of some kind. Further north, four archaeological markers attest to the road running across the Gers plain (figs 7a, 7b, 8, 9a, 9b, 10a, 10b).
THE COURSE OF THE ROAD FROM LECTOURE TO AGEN.
Two routes have been proposed between Lectoure and Agen (fig. 11). The first, on the left bank of the Gers is a ridge route, the Peyrigne, that formed a major north-south highway from protohistoric times. Above all, excavation of it in Nitiobroges territory (fig. 12), at the southern exit from Aginnum, has confirmed its dating to Antiquity. Beside the roads stood twin mausolea, whose ostentation emphasized the early take-up by local elites of new funerary fashions. The course of the Peyrigne can be followed between Agen and Lectoure : it crossed Nitiobroges’ lands along the hills and joined the Gers valley downstream of Lectoure. No clear archaeological data indicates the course along this long stretch of road between the two capitals. The second route, over the plateaux of the right bank of the Gers, is characterized in a document of 1352 as Itineris Magni, which leads to it being associated with Antiquity. It is known above all from a straight stretch of road 10 km long between Lectoure and Astaffort. An old excavation near the village of Sempesserre supposedly unearthed the roadway paved with large slabs. This robust surfacing and the straight course of the road have long argued in favour of it being from Antiquity. However, present-day knowledge of the structures of the roadway show that the presence of paving slabs is rare, with most of the surfacing being simply broken stone. Moreover, examination of the Napoleonic cadastre reveals the presence of land plots ante-dating the road (figs 14 and 15), giving little credit to the hypothesis that the road was of an early date. Accordingly the Roman road of the Antonine Itinerary must have pretty much followed the course of the Peyrigne. Although the appraisal of data from Antiquity, archaeological records and topographic constraints does not put paid to the question of the roadway of the Antonine Itinerary, it does invite us to come off the fence with regard to the best documented hypotheses. For the Auch/Saint-Bertrand-de-Comminges, section, the most convincing arguments, first among which are the credible location of the Belsino road station and the position of the milestone of Castelnau-Magnoac, argue for a course of the road in the Itinerary via the ridge above the left bank of the River Gers. This pathway could have extended that of what is called the Peyrigne in the areas around Lectoure and Agen. For the Auch-Lectoure section, there is plentiful archaeological data enabling the course of the road to be traced across the Gers floodplain. Last, for the Lectoure-Agen section, the Peyrigne, the use of which in Antiquity is attested, may have been conflated with the Roman road of the Antonine Itinerary, even if this hypothesis can only yet be corroborated by the absence of probatory data about an alternative route. In southern Aquitaine, in imperial times, the road of the Itinerary formed the main backbone between the Pyrenees and the Garonne. It continued straight on northwards as far as Limoges where it joined the “via Agrippa” between Saintes and Lyon.