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Résumé

The partial excavation of an outwork of the Soissons (Aisne) urban fortification, built and dismantled during the 19th century, has provided an opportunity to compare the abundant archival documentation relating to this feature and field observations. Archaeology makes it possible to verify the reliability of written sources and to shed light on those parts of the history of the fortification not covered by the texts. Therefore, this research study allows to follow the evolution of a structure from the preliminary project up to its dismantling, via its construction and its functioning hazards. At the end of this study, it is possible to measure the relevance of excavating a recent structure, despite the great number of preserved archival records.

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Notes de la rédaction

This article is long summary of the French article “L’ouvrage à cornes de Saint-Jean à Soissons : vestiges archéologiques et essai de contexte historique”, Archéologie médiévale [Online], 49, 2019, online since 3 February 2020. URL: http://journals.openedition.org/archeomed/24749; DOI: https://doi.org/10.4000/archeomed.24749.

Texte intégral

  • 1 Under the responsability of Vincent Buccio (Desenne, Flucher, Pinard 2003; Buccio 2011).

1The town of Soissons is positioned on a meander of the Aisne valley, north-east of Paris (fig. 1), which gave its strategic location. The dig of the Gouraud barracks, on a promontory (the Mont-Saint-Jean) located today in town, has brought to light a part of the 19th century defensive system, in particular the scarp, the ditch and an outwork’s defence reduit1. The aim of this article is to connect the data derived from the excavation to the abundant preserved archive file, and to show, through a specific example, the relevance of excavating a well-documented recent structure.

Fig. 1 Location map.

Fig. 1 Location map.

OpenStreetMap data.

An abundant documentary file

  • 2 Leclercq de Laprairie 1853.
  • 3 Pérouse de Montclos 1972, p. 493.
  • 4 Brialmont 1869, p. 2; Faucherre et François 2011, p. 69.

2The Mont-Saint-Jean, located outside the fortress southward of the medieval town (fig. 2), largely dominates. A hornwork, separate from the town wall, is probably built in the second half of the 16th century2, but it is almost completely destroyed, presumably in the middle of the 17th century; in any case, a new structure, another hornwork, is built in the 19th century. The latter is particularly well-documented: if the first projects are drawn-up in 1817, its construction extended from 1837 to 1847, while the project gradually evolves. This evolution affects both the structure’s morphology as well as its designation. At first it was categorised as a “lunette”, it becomes a “hornwork” from 1841. Hornworks are formed by a bastioned face between two wings that connect the hornwork to the rear.3 In fact, the structure that was built is an intermediate solution between these two types: the two demi-bastions and the reduit that were built are not connected to the town’s scarp by two wings, but by a simple ditch (fig. 4). Once again outdated by the development of rifled artillery in the middle of the 19th century, the fortress remained active until its final decommissioning in 1885. The dismantling of urban fortifications at the end of the 19th century is very poorly documented4, but is illustrated by a few postcards, which shed light on certain details of this destruction; the ditch is first partly filled, then the stone casing is repurposed while the rubble filling is tipped in the ditch. In some cases, wagons were used to recover the materials.

Fig. 2 Superimposition of the routes of the different city walls on the 1842 map (knowledge status of 1842), Service historique de la Défense, 1VH2102.

Fig. 2 Superimposition of the routes of the different city walls on the 1842 map (knowledge status of 1842), Service historique de la Défense, 1VH2102.

Shot V. Buccio.

Fig. 4 Denomination of the different elements of the structure on the project plan of 1842, Archives départementales Aisne, 3J680.

Fig. 4 Denomination of the different elements of the structure on the project plan of 1842, Archives départementales Aisne, 3J680.

CAD V. Buccio.

3The plans produced by the Military Engineers show contour lines that were measured before the construction of the structure and contour lines of the project itself. The comparison of this data with the altitudes measured on the field allows us to precisely assess the distribution of the earthworks (the volume of which was calculated in the 1840s). Especially, considering that the bottom of the ditch coincides, within a few decimetres, with the one uncovered, we can establish the height of the different structures observed and especially measure the importance of the levelling of the Mont-Saint-Jean for the construction of the hornwork. The volumes of earth moved represent almost 130,000 m3, of which 26,800 m3 was for the southern demi-bastion. Most of the earth came from the digging of the ditch and supplied the land fill but the preparations of the embankments also led to a number of excavations.

  • 5 The counterscarp and its facilities were outside of the excavation limits.

4The excavation, which related to the southern wing, made it possible to study the ditch in front of the structure (fig. 12, structure 1), the scarp (structure 2) and a building excavated at the rear (structure 3)5. It yielded very little artefacts, and it does not further our understanding or provide any dating. The virtual absence of archaeological artefacts, despite the proximity with the ancient necropolis and the medieval abbey of Saint-Jean, is equally remarkable.

Fig.12 General plan of the excavation.

Fig.12 General plan of the excavation.

CAD V. Buccio.

A frequented ditch (structure 1)

5The ditch (preserved depth: 4.90 m) was dug between 1842 and 1843 largely in the geological substratum. A trampled layer of silty sediment was deposited at its base during the fortification’s use. The filling of the ditch is made up of sand without any exogenous elements; however, there are occasional block deposits which mark the destruction of the upper levels of the structure.

6The scarp’s stone casing contains 62 graffiti carried out on the courses that are attainable from the bottom of the ditch. Most of them are inscriptions by soldiers, particularly relating to troop movements; there are also a few drawings (profiles, a crude boat), counts and musical notations. The latter might have been drawn by the regiment’s drum school, which practised there.

The scarp (structure 2)

7The scarp wall was uncovered over a total length of almost 75 m. The ditch serves as a foundation trench for the scarp; the construction leans against the edge of the excavation. The foundations of the wall take hold at a depth of 0.75 m from the bottom of the ditch. They are more than 4 m wide and are built of limestone bound by a hard pink mortar; the rubble fill is very irregular. The foundations protrude 0.60 m from the scarp, but are at the same level as the elevation on the substratum side.

8The scarp consists of a wall 3.60 m wide at the top and 4 m at the base, reinforced at regular intervals by stone buttresses located on the internal face of the structure, to which they are bonded. These buttresses are trapezoidal. They are inserted into notches provided in the foundation trench. The wall and its buttresses consist in two faces between which there is a rubble fill; the latter is composed of irregular blocks and reused materials.

  • 6 Lecer 1912; Urbain 2007

9The internal face is built in roughly squared stone bound with a hard lime mortar. The external face, slightly sloped (constant slope of 5 cm by meter), intended to be visible, is very regular: its courses are perfectly horizontal. Most of the units are made up of stretchers, with some headers placed at regular intervals. The stones that form the first two courses and the quoins are large: their maximum length is 2.04 m, their height is 0.35 m; a very hard limestone was used for these units, a softer limestone was used for elevation. The average height of the upper courses is 0.32 m (0.29 to 0.35 m) and the length of the stones is 0.80 m on average. The joints are very thin and regular, of a maximum width of 5 mm and are slicked. The lime mortar which binds the stones is pink, tender and brittle. The pink coloration is probably due to the presence of crushed terra cotta, as planned by the Military Engineers. The majority of the stones have a very smooth outer surface, indicating that the blocks were polished after being cut. Repairs on the units that visibly followed three impacts attest to the military role of the structure, that must be linked to the only military episode that Soissons faced, the War of 18706.

10Reused stone found in the rubble fill were uncovered when the scarp wall was demolished. Among other elements, a fragment of a statue showing a very eroded drape (fig. 18) evokes the regional statuary of the late 12th and 13th centuries.

Fig. 18 Reused stone: drape, statuary fragment.

Fig. 18 Reused stone: drape, statuary fragment.

Shot CG Aisne.

11A cornice similar to those of the cloister of Saint-Jean-des-Vignes attributed to the second half of the 13th century was also uncovered, as have numerous architectural blocks. The ensemble could have come from the abbey of Saint-Jean-des-Vignes or from another nearby church, destroyed in the 15th century.

A gunpowder magazine (structure 3)?

  • 7 SHD 1 VH 2102, article 8, section 3, carton 22.

12Inside the town wall, the dig revealed an excavated building with two aisles connected by an opening. The overall width of this structure is 9.5 m and its length is 18 m. Its axis is close to the bisector of the angle of the horn. The observed depth of its excavation is 2.30 m in relation to the preserved surface of the ground. The foundation of a probable staircase is visible. Inside, an organic layer 0.07 m thick seems to materialise the remains of a floor, possibly mulched. Some of the walls were probably damaged by the scarp’s construction, but most of them were erected after it was built. A military memoir from 18477 depicts an underground passageway of the hornwork’s left demi-bastion, which probably is the structure. The latter would therefore have been installed shortly after the completion of the hornwork, and seems to have served as a gunpowder magazine.

13This excavation is a source of information on local urban history, on military practices and on the implementation of military projects in the 19th century. Associating the excavation and the documentary study shows the complementarity of the two methods, without one being subordinate to the other.

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Bibliographie

Brialmont A.-H.

1869, Traité de fortification polygonale, Paris, Dumaine, 2 vol.

Buccio V.

2011, Soissons (Aisne), ancienne caserne Gouraud, rapport final d’opération de fouille archéologique préventive, Laon, CG Aisne, 2 vol.

Desenne S., Flucher G. et Pinard E.

2003, Soissons « Caserne Gouraud », rapport de diagnostic, Amiens, Inrap.

Faucherre N. et François S.

2011, Places fortes, bastion du pouvoir, Paris, Rempart.

Lecer

1912, « Documents relatifs à la défense de Soissons en 1870 », Bulletin de la Société historique et archéologique de Soissons, 3e série, t. XIX, p. 89-155.

Leclercq de Laprairie

1853, « Les fortifications de Soissons aux différentes époques de son histoire », Bulletin de la société historique et archéologique de Soissons, 1re série, t. VII, p. 199-248.

Pérouse de Montclos J.-M.

1972, Architecture, méthode et vocabulaire, Paris, Imprimerie nationale.

Urbain N.

2007, « Soissons et la guerre de 1870-1871 », L’Aisne envahie, dans Mémoires – Fédération des sociétés d’histoire et d’archéologie de l’Aisne, t. LII, p. 137-168.

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Notes

1 Under the responsability of Vincent Buccio (Desenne, Flucher, Pinard 2003; Buccio 2011).

2 Leclercq de Laprairie 1853.

3 Pérouse de Montclos 1972, p. 493.

4 Brialmont 1869, p. 2; Faucherre et François 2011, p. 69.

5 The counterscarp and its facilities were outside of the excavation limits.

6 Lecer 1912; Urbain 2007

7 SHD 1 VH 2102, article 8, section 3, carton 22.

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Table des illustrations

Titre Fig. 1 Location map.
Crédits OpenStreetMap data.
URL http://journals.openedition.org/archeomed/docannexe/image/31040/img-1.jpg
Fichier image/jpeg, 497k
Titre Fig. 2 Superimposition of the routes of the different city walls on the 1842 map (knowledge status of 1842), Service historique de la Défense, 1VH2102.
Crédits Shot V. Buccio.
URL http://journals.openedition.org/archeomed/docannexe/image/31040/img-2.jpg
Fichier image/jpeg, 473k
Titre Fig. 4 Denomination of the different elements of the structure on the project plan of 1842, Archives départementales Aisne, 3J680.
Crédits CAD V. Buccio.
URL http://journals.openedition.org/archeomed/docannexe/image/31040/img-3.jpg
Fichier image/jpeg, 981k
Titre Fig.12 General plan of the excavation.
Crédits CAD V. Buccio.
URL http://journals.openedition.org/archeomed/docannexe/image/31040/img-4.jpg
Fichier image/jpeg, 353k
Titre Fig. 18 Reused stone: drape, statuary fragment.
Crédits Shot CG Aisne.
URL http://journals.openedition.org/archeomed/docannexe/image/31040/img-5.jpg
Fichier image/jpeg, 506k
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Référence électronique

Vincent Buccio, « The Saint-Jean hornwork in Soissons: archaeological remains and historical context [abridged version] »Archéologie médiévale [En ligne], 49 | 2019, mis en ligne le 30 avril 2021, consulté le 18 octobre 2021. URL : http://journals.openedition.org/archeomed/31040 ; DOI : https://doi.org/10.4000/archeomed.31040

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Auteur

Vincent Buccio

Service départemental d’archéologie des Alpes-de-Haute-Provence, associate members CIHAM-UMR 5648

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Traducteur

Leila Tickner

Technical translator

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Licence Creative Commons
la revue Archéologie médiévale est mise à disposition selon les termes de la Licence Creative Commons Attribution - Pas d’Utilisation Commerciale 4.0 International.

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