The Antonine Wall

Antonine wall at Barr Hill near Twechar. Tony Rotondas, CC BY-SA 3.0

The Vallum Antonini or Antonine Wall runs for 39 miles west to east from Old Kilpatrick on the Firth of Clyde to Bo’ness on the Firth of Forth. Built between 142 to 154 AD the wall briefly represented the northernmost extent of the Limes Romanus, separating the province of Britannia from Caledonia until its abandonment and the withdrawal of Roman forces to Hadrian’s Wall . Its construction was ordered by Emperor Antoninus Pius (138-161 AD) to coincide with a new northward advance led by the Roman Governor Quintus Lollius Urbicus into the area that now forms lowland Scotland. The exact reason for building the wall is not clear but it is probable that it was in response to unrest and revolt by the Brigantes, the dominant Celtic tribe in what today is northern England, and an outburst of fort building by the indigenous population in the central and eastern lowlands of Caledonia. By extending the defended frontier northward from Hadrian’s Wall the Roman’s could more effectively prevent Brigantian collusion with Caledonian tribes while creating a buffer zone and two-tier line of defence against Caledonian incursions.

Unlike Hadrian’s Wall the Antonine Wall was built of turf on a stone foundation and typically consisted of a layered turf rampart some 10 feet in height with a deep v-shaped ditch on the northern side. Spoil from the ditch was utilised to construct an outer mound to the north of the ditch itself. To the south of the rampart ran a military service road to facilitate communication along the length of the wall. Construction was carried out by the three Roman legions stationed in Britannia, the the II Augusta based at Isca (Caerleon), the VI Victrix based at Eboracum (York) and the XX Valeria Victrix based at Deva Victrix (Chester) following a military campaign in 141 AD to gain control of the region between the line of Hadrian’s Wall and the line of the Firth of Cylde and Firth of Forth. A wooden fence and walkway may have surmounted the turf rampart.

Remains of a Fort on the Antonine wall at Barr Hill near Twechar. CC BY-SA 3.0

Six forts were originally planned to line the wall at intervals of 6 miles. This plan was later revised, with forts appearing every 2 miles, with seventeen in total being constructed. While smaller than forts in the rest of Britannia and throughout the Empire, those constructed on the Antonine wall followed the classic rectangular design and layout of Roman forts. Like the wall they were constructed primarily of turf. In addition to the forts at least nine ‘fortlets’ were constructed with an assumed spacing of 1 Roman mile to house smaller garrisons to facilitate co-ordination of defence, signalling, and communication between the more widely spaced forts. After construction was completed the wall was predominately manned by auxiliary troops with small Legionary detachments.

From inscriptions found at the wall at least nine Auxiliary units have been identified drawn from modern day Belgium (The First Cohort of Tungrians, The First Tungrian Wing, and The Sixth Cohort of Nervians), Bulgaria (The Second Cohort of Thracians), France (The First Cohort of Tungrians, and the The Fourth Cohort of Gauls), Netherlands (The First Cohort of Baetasians), Spain (The First Cohort of Vardullians), and Syria (The First Cohort of Hamians), the last being the only known unit of archers in Britannia.

Though clear evidence is lacking it seems apparent that the wall was abandoned by c.165 AD in the face of increasing hostility and unrest from the Brigantes and Caledonia. The Roman Governors of Britain, Gnaeus Julius Verus (154-158) and Sextus Calpurnius Agricola (163-166) were both involved in suppressing revolts in the north, with Agricola withdrawing troops southward to Hadrian’s Wall to counter the threat of further rebellion, and evidence from wall forts at Rough Castle, Castlecary and Balmuildy, shows signs of fighting and fire damage dated to c.155 AD.

The withdrawal was effectively permanent, fixing the border of Britannia at Hadrian’s Wall. In 180 AD Ulpius Marcellus was sent to Britannia to suppress a revolt during which Hadrian’s Wall had been breached by Caledonian tribes. Marcellus’ response took the Legions north of the border and it is possible that the Antonine Wall was briefly reoccupied at this time. Any such occupation was short-lived as Marcellus withdrew to Hadrian’s Wall, abandoning forts to the north such as Newstead.

In 195 AD Marcellus’ successor as governor Clodius Albinus led the British legions into Gaul during his revolt against the Emperor, Septimus Severus. With the garrisons at Hadrian’s Wall and the military towns depleted the Mæatae, a confederation of tribes from beyond the Antonine Wall, seized their moment. Hadrian’s Wall was occupied and destroyed, as were York and Chester. The defeat of Albinus at the Battle of Lugdunum in 197 AD saw the British Legions, much depleted in number, sent back to Britannia by Severus under the governorship of Virius Lupus. With insufficient military resources to mount a successful campaign Lupus bought the Mæatae off, restoring a semblance of peace to the province and began work on rebuilding the forts and Hadrian’s Wall which was completed by c.206 AD under Lucius Alfenus Senecio.

With order restored elsewhere in the Empire, Severus arrived in Britannia in 208 AD with the aim of conquering Caledonia. His first action was to instigate a massive building project to replace the turf and timber sections of Hadrian’s Wall with stone while he marched north with his Legions to reconquer the area up to the line of the Antonine Wall, which was also restored. Having established control Severus marched into Caledonia in 209, rebuilding and garrisoning many of the forts constructed by Gnaeus Julius Agricola during his campaigns in Caledonia in 83-84 AD, and carrying out acts of widespread devastation in areas the Legions could not directly control.

Unable, or perhaps unwilling, to meet Severus in open battle the Caledonians fought a guerrilla campaign against Severus’ punitive expeditions. Despite inflicting reputed heavy casualties on the Roman forces the Caledonians sued for peace in early 210, only to revolt together with the Mæatae later in the year. By late 210 Severus was preparing a campaign to complete the conquest of Caledonia when he fell ill. Severus, then aged 65, withdrew to Eboracum where he died on 4 February, 211. His sons, Lucius Septimius Bassianus, ‘Caracalla’, and Publius Septimius Antoninus Geta, were jointly declared emperors by the Legions. Caracalla, keen to consolidate his position in Rome, called off the campaign. The frontier was once more withdrawn back from the Antonine Wall to Hadrian’s Wall marking the effective end of Roman ambitions in Caledonia.

Portrait of Antoninus Pius (86–165 AD. © Marie-Lan Nguyen / Wikimedia Commons / CC-BY 2.5

Limes Romanus

Limes, (Latin: “path”), plural limites, in Ancient Rome, originally a path that marked a boundary between plots of land. The meaning evolved over time and later came to mean a frontier. A network of forts, roads, and watchtowers were concentrated along the limes and in many places a continuous barrier was constructed. British readers will be most familiar with the stone built Hadrian’s Wall between the Tyne and Solway, and the turf built Antonine Wall between the Forth and Clyde. The Saxon Shore, a series of fortifications along both sides of the English Channel, were constructed in the 3^rd  century AD and though their original purpose is open to debate, by the 4^th Century the forts were employed in operations against Frankish and Saxon pirates. On the continent the Limes Germanicus connected the Lower Rhine at Katwijk to the Danube, while the Danube itself, together with the Limes Moesiae, formed the line of the limes between Germania and the Black Sea. The limes were a vital feature of Imperial defence and provided a cordon which deterred casual incursion and would trigger counter-measures against more serious attacks. The limes marked the lands which were subject to Roman authority from those were not, and to cross the limes one had to pay portaria and accept the Empire’s authority. Their most important characteristic was their continuity, running without a break whether as a continuous wall, stockaded earthworks, or string of fortified points, along the entire length of the Imperial frontier. Ultimately they proved inadequate defences with the coup de grace in the fall of Rome being delivered in 476 with the deposition of the last of the Roman Emperors, Romulus Augustus, by the German Odoacer.