The Hadrian Wall lost its importance when Roman Emperor Hadrian’s successor, Antonius Pius (138 – 161), who launched a successful military campaign in southern Scotland early in his reign, began to construct the Antonine Wall.
The Romans started to build the Antonine Wall in Britain only fifteen years after the construction of Hadrian’s Wall was completed. It is known that the famous Hadrian’s Wall was built for both military and economic needs. It was also important that construction would prevent raiders from the north from destroying the strategic Roman base at Corbridge, in Northumberland.
The Antonine Wall was constructed by another second-century emperor even further north of Hadrian’s Wall. The unrest from the north must have been palpable to dictate the construction of such massive formations. From 155 to 157 CE, the Brigantes – ancient Britons, who in pre-Roman times controlled the largest section of what would become Northern England – revolted in Scotland.
The Antonine Wall’s ruins are unfortunately less visible than those of the Hadrian’s Wall. This is mainly due to the unstable building material – turf, which was used for the construction of the wall. However, it is evidenced by the construction of foundations that the Romans planned to erect a stone wall.
The soldiers of the Second Augusta, the Sixth Victrix, and the Twentieth Valeria Victrix legions (also responsible for the building of Hadrians Wall) began to construct the Antonine Wall in AD 142 at the order of Roman Emperor Antoninus Pius.
The structure that runs across what is now the Central Belt of Scotland, between the Firth of Forth and the Firth of Clyde, was the Roman Empire’s northernmost frontier barrier.
The work took about 12 years to complete. These legions erected stone slabs on completion of their work and these slabs are the records of the length of the wall they completed, the emperor’s name, and the name of the legion.
The slabs are unique because no similar slabs are known from any frontier of the Roman Empire.
Originally six forts were planned (Carriden, Mumrills, Castlecary, Bar Hill, Balmuildy, and Old Kilpatrick) with several fortlets built in between. Later, these fortlets were abandoned and the next ones were constructed.
The Antonine Wall (named after the Roman emperor Antoninus Pius) was an impressive embankment with a height of 4 meters, 4.3 meters wide, with a large ditch on the north side for reinforcement of defense and a network of roads on the south side for the efficient movement of troops. It was 63 km (39 miles) long with 19 forts located every 3.3 km.
As early as 162 AD (only eight years after its completion), the Romans from this line were forced to retreat to the south again and returned to the older fortification – Hadrian’s Wall – after it was additionally strengthened.
Unfortunately for the Romans, the wall was abandoned, then recaptured a year later, and finally, completely abandoned by 164 CE.
Archaeological excavation conducted in the ruins of the Wall revealed many Roman artifacts, both the military and the domestic. When the Romans were abandoning a fort, they usually buried many of the possessions that they did not wish to salvage and take with them. They did not want them to be used by local people.
Except for decorative slabs, the Romans also left altars, tombstones, personal possessions, and building materials, which were well-buried and therefore were unearthed well-preserved and never touched by robbers.