Portus Adurni
Encyclopedia
Portus Adurni was a Roman fortress
in the Roman province
of Britannia
. Listed in the Notitia Dignitatum
, it is generally accepted as having been located at adjoining Portchester
in the English
county of Hampshire
and was later converted into a medieval
castle
known as Portchester Castle
. It is the best preserved Roman fort north of the Alps.
forts in the 5th century Notitia Dignitatum
, and the name is usually identified with Portchester, although it has occasionally been identified with the Roman fort at Walton Castle, Suffolk (which has now disappeared into the sea). Portus Adurni may be identical with the Ardaoneon listed in the Ravenna Cosmography
, and Rivet and Smith derive both names from the British
"ardu-" meaning "height". This derivation fits Portchester (which lies beneath Portsdown Hill
) better than a flat location such as Walton Castle.
was built during the 3rd century to protect the southern coastline of Britain
from possibly Saxon raiders (part of the Saxon Shore) and occupies a commanding position at the head of Portsmouth Harbour
. The fort is square, enclosing an area of 9 acres (36,000 m²) with outer walls 20 feet (6 m) high, 10 feet (3 m) thick, 210 yards (200 m) long and constructed of coursed flint
bonded with limestone
slabs. Square shaped forts became widely used during the third century, being highly practical and defensible. Portus Adurni boasts towers all along the walls, as well as towers that angle out at the corners. Historians feel this paramount concern for defensibility may reflect the seriousness of the Saxon raids during this time or the defensive holding point of Carausian Revolt
(see below). The gates of Portus Adurni are of particular interest, they are indented inwards, so as to trap the enemy in an area exposed to walls on three sides, this technique became widely used from the Augustinian age to the fall of the Empire.
Unusual for a building of this period, the majority of the walls and bastions are complete. It has lost only four of its bastions and, although the walls themselves have been quarried to provide stone for later additions, from the outside at least, they appear much as they did when they were first built. The walls were made in groups, by groups of gangs, which explains the different textures as you walk along the outerperimeter.
. These forts became defensive holding points for the rebel Carausius
, who in 285 was given the task of fixing the Saxon piracy problem in the English Channel. Carausius was eventually charged with keeping the pirate's booty for himself, at which point he retreated to Britain and proclaimed himself Emperor. The revolt went on for close to 10 years as other Roman generals tried and failed to dislodge him until he was eventually murdered by one of his aides, Allectus in 293, and Britain was finally taken back by 296. There is still a question as to who built Portus Adurni. While some of the Saxon shore forts were built under previous commanders and emperors, some were built by Carausius during his revolt. Evidence suggests that Portus Adurni was built during the time of Carausius. Of the coinage uncovered at the site, a large portion were minted by Carausius acting as emperor during the time of his revolt.
Portus Adurni's location and strong walls made it attractive as a fortress. The fort became an Anglo-Saxon
high-status residence with great hall and tower. Later the Roman gateways were rebuilt as well.
castle and later medieval palace. It was used as a gaol
during the Napoleonic Wars
. Its exceptional condition can therefore be attributed to the fact that, despite short periods of abandonment and longer periods of neglect, the fort was occupied for almost sixteen centuries. The site is owned by the Southwick Estate but managed by English Heritage
and is open to visitors throughout the year.
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
in the Roman province
Roman province
In Ancient Rome, a province was the basic, and, until the Tetrarchy , largest territorial and administrative unit of the empire's territorial possessions outside of Italy...
of Britannia
Britannia
Britannia is an ancient term for Great Britain, and also a female personification of the island. The name is Latin, and derives from the Greek form Prettanike or Brettaniai, which originally designated a collection of islands with individual names, including Albion or Great Britain. However, by the...
. Listed in the Notitia Dignitatum
Notitia Dignitatum
The Notitia Dignitatum is a unique document of the Roman imperial chanceries. One of the very few surviving documents of Roman government, it details the administrative organisation of the eastern and western empires, listing several thousand offices from the imperial court down to the provincial...
, it is generally accepted as having been located at adjoining Portchester
Portchester
Portchester is a locality and suburb 10km northwest of Portsmouth, England. It is part of the borough of Fareham in Hampshire. Once a small village, Portchester is now a busy part of the expanding conurbation between Portsmouth and Southampton, on the A27 main thoroughfare...
in the English
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
county of Hampshire
Hampshire
Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...
and was later converted into a medieval
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
castle
Castle
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...
known as Portchester Castle
Portchester Castle
Portchester Castle is a medieval castle built within a former Roman fort at Portchester to the east of Fareham in the English county of Hampshire. Probably founded in the late 11th century, Portchester was a baronial castle that was taken under royal control in 1154. The monarchy controlled...
. It is the best preserved Roman fort north of the Alps.
Identification
The name Portus Adurni appears only in the list of Saxon ShoreSaxon Shore
Saxon Shore could refer to one of the following:* Saxon Shore, a military command of the Late Roman Empire, encompassing southern Britain and the coasts of northern France...
forts in the 5th century Notitia Dignitatum
Notitia Dignitatum
The Notitia Dignitatum is a unique document of the Roman imperial chanceries. One of the very few surviving documents of Roman government, it details the administrative organisation of the eastern and western empires, listing several thousand offices from the imperial court down to the provincial...
, and the name is usually identified with Portchester, although it has occasionally been identified with the Roman fort at Walton Castle, Suffolk (which has now disappeared into the sea). Portus Adurni may be identical with the Ardaoneon listed in the Ravenna Cosmography
Ravenna Cosmography
The Ravenna Cosmography was compiled by an anonymous cleric in Ravenna around AD 700. It consists of a list of place-names covering the world from India to Ireland. Textual evidence indicates that the author frequently used maps as his source....
, and Rivet and Smith derive both names from the British
British language
The British language was an ancient Celtic language spoken in Britain.British language may also refer to:* Any of the Languages of the United Kingdom.*The Welsh language or the Brythonic languages more generally* British English...
"ardu-" meaning "height". This derivation fits Portchester (which lies beneath Portsdown Hill
Portsdown Hill
Portsdown Hill is a long chalk hill in Hampshire, England, offering good views over Portsmouth, The Solent, Hayling Island and Gosport, with the Isle of Wight beyond. The hill is on the mainland, just to the north of Ports Creek, which separates the mainland from Portsea Island, on which lies the...
) better than a flat location such as Walton Castle.
Roman fort
The fortCastra
The Latin word castra, with its singular castrum, was used by the ancient Romans to mean buildings or plots of land reserved to or constructed for use as a military defensive position. The word appears in both Oscan and Umbrian as well as in Latin. It may have descended from Indo-European to Italic...
was built during the 3rd century to protect the southern coastline of Britain
Roman Britain
Roman Britain was the part of the island of Great Britain controlled by the Roman Empire from AD 43 until ca. AD 410.The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia...
from possibly Saxon raiders (part of the Saxon Shore) and occupies a commanding position at the head of Portsmouth Harbour
Portsmouth Harbour
Portsmouth Harbour is a large natural harbour in Hampshire, England. Geographically it is a ria: formerly it was the valley of a stream flowing from Portsdown into the Solent River. The city of Portsmouth lies to the east on Portsea Island, and Gosport to the west on the mainland...
. The fort is square, enclosing an area of 9 acres (36,000 m²) with outer walls 20 feet (6 m) high, 10 feet (3 m) thick, 210 yards (200 m) long and constructed of coursed flint
Flint
Flint is a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones. Inside the nodule, flint is usually dark grey, black, green, white, or brown in colour, and...
bonded with limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
slabs. Square shaped forts became widely used during the third century, being highly practical and defensible. Portus Adurni boasts towers all along the walls, as well as towers that angle out at the corners. Historians feel this paramount concern for defensibility may reflect the seriousness of the Saxon raids during this time or the defensive holding point of Carausian Revolt
Carausian Revolt
The Carausian Revolt was an episode in Roman history, during which a Roman naval commander, Carausius, declared himself emperor over Britain and northern Gaul. His Gallic territories were retaken by the western Caesar, Constantius Chlorus, in 293, after which Carausius was assassinated by his...
(see below). The gates of Portus Adurni are of particular interest, they are indented inwards, so as to trap the enemy in an area exposed to walls on three sides, this technique became widely used from the Augustinian age to the fall of the Empire.
Unusual for a building of this period, the majority of the walls and bastions are complete. It has lost only four of its bastions and, although the walls themselves have been quarried to provide stone for later additions, from the outside at least, they appear much as they did when they were first built. The walls were made in groups, by groups of gangs, which explains the different textures as you walk along the outerperimeter.
History
The Saxon shore forts, including Portus Adurni, were built during the mid to late 3rd century amid increased instability in northern eastern Gaul and the Rhineland, eventually leading to the Roman evacuation of this area. The forts were intended to maintain control over the region, monitor crucial shipping and trade, as well as defend against raids from across the English ChannelEnglish Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
. These forts became defensive holding points for the rebel Carausius
Carausius
Marcus Aurelius Mausaeus Valerius Carausius was a military commander of the Roman Empire in the 3rd century. He was a Menapian from Belgic Gaul, who usurped power in 286, declaring himself emperor in Britain and northern Gaul. He did this only 13 years after the Gallic Empire of the Batavian...
, who in 285 was given the task of fixing the Saxon piracy problem in the English Channel. Carausius was eventually charged with keeping the pirate's booty for himself, at which point he retreated to Britain and proclaimed himself Emperor. The revolt went on for close to 10 years as other Roman generals tried and failed to dislodge him until he was eventually murdered by one of his aides, Allectus in 293, and Britain was finally taken back by 296. There is still a question as to who built Portus Adurni. While some of the Saxon shore forts were built under previous commanders and emperors, some were built by Carausius during his revolt. Evidence suggests that Portus Adurni was built during the time of Carausius. Of the coinage uncovered at the site, a large portion were minted by Carausius acting as emperor during the time of his revolt.
Anglo-Saxon high-status residence
Even after the departure of the Roman ArmyRoman army
The Roman army is the generic term for the terrestrial armed forces deployed by the kingdom of Rome , the Roman Republic , the Roman Empire and its successor, the Byzantine empire...
Portus Adurni's location and strong walls made it attractive as a fortress. The fort became an Anglo-Saxon
Anglo-Saxons
Anglo-Saxon is a term used by historians to designate the Germanic tribes who invaded and settled the south and east of Great Britain beginning in the early 5th century AD, and the period from their creation of the English nation to the Norman conquest. The Anglo-Saxon Era denotes the period of...
high-status residence with great hall and tower. Later the Roman gateways were rebuilt as well.
Later history
The circuit walls of the fort became the outer bailey wall of a NormanNorman architecture
About|Romanesque architecture, primarily English|other buildings in Normandy|Architecture of Normandy.File:Durham Cathedral. Nave by James Valentine c.1890.jpg|thumb|200px|The nave of Durham Cathedral demonstrates the characteristic round arched style, though use of shallow pointed arches above the...
castle and later medieval palace. It was used as a gaol
Prison
A prison is a place in which people are physically confined and, usually, deprived of a range of personal freedoms. Imprisonment or incarceration is a legal penalty that may be imposed by the state for the commission of a crime...
during the Napoleonic Wars
Napoleonic Wars
The Napoleonic Wars were a series of wars declared against Napoleon's French Empire by opposing coalitions that ran from 1803 to 1815. As a continuation of the wars sparked by the French Revolution of 1789, they revolutionised European armies and played out on an unprecedented scale, mainly due to...
. Its exceptional condition can therefore be attributed to the fact that, despite short periods of abandonment and longer periods of neglect, the fort was occupied for almost sixteen centuries. The site is owned by the Southwick Estate but managed by English Heritage
English Heritage
English Heritage . is an executive non-departmental public body of the British Government sponsored by the Department for Culture, Media and Sport...
and is open to visitors throughout the year.
External links
- Portchester Castle
- A Guide to Portchester Castle Times, prices and visitor information.