A beginner’s guide to the words used to describe Roman Scotland
Roman archaeology comes with its own vocabulary.
Archaeologists talk about fortlets, annexes, cropmarks, ramparts, vici and marching camps. Roman military sites contain buildings called the principia, praetorium and horreum. Excavation reports may use expressions such as terminus post quem or describe a site as Flavian, Antonine or Severan.
You do not need to be an archaeologist — or know Latin — to understand them.
This glossary explains some of the terms used across Romans in Scotland, with particular emphasis on Roman forts, temporary camps, the Antonine Wall and the archaeological evidence found in Scotland.
Quick guide: fort, fortlet, fortress or camp?
These four words are easily confused.
Fortress
A legionary fortress was a very large permanent military base designed to accommodate most or all of a Roman legion — several thousand soldiers.
Inchtuthil, near Dunkeld, is Scotland’s outstanding example.
Fort
A fort was smaller than a legionary fortress and usually housed an auxiliary unit or part of one.
Roman Scotland contains many forts, including Ardoch, Newstead, Birrens, Cramond, Bearsden and Rough Castle.
Fortlet
A fortlet was a much smaller defended military post occupied by a small detachment rather than an entire regiment.
Fortlets might guard roads, crossings or frontier points.
A remarkable sequence of them was constructed along the Antonine Wall.
Marching camp
A marching camp, or temporary camp, was built to protect an army that was temporarily stopping at a location.
Unlike a fort, it was not normally intended as a permanent base.
Scotland contains an exceptional number of Roman temporary camps, providing evidence for the movement of Roman armies through the landscape.
Explore: Roman Forts in Scotland | Roman Fortlets in Scotland | Inside a Roman Marching Camp
A
Agger
An agger is an earth bank or rampart.
In a Roman temporary camp, soil dug from the defensive ditch could be piled inward to help create the camp’s rampart.
The word can also be used for raised Roman road embankments, so its precise meaning depends on the context.
Aerial photography
Many archaeological sites are discovered or better understood from photographs taken from the air.
Buried ditches, walls and buildings can affect the soil and crops growing above them. From ground level nothing may be visible, but from the air their outlines can appear dramatically.
Aerial photography has been especially important in identifying Roman marching camps in Scotland.
See also: Cropmark
Annexe
An annexe is an enclosed area attached to, or immediately beside, a Roman fort or fortlet.
It might be surrounded by its own ditch or rampart.
Annexes could contain roads, buildings, workshops or other activities associated with the military installation, but archaeologists should not automatically assume that every annexe had the same function.
Sites such as Birrens and Strageath contain important examples.
Antonine
Archaeologists describe something as Antonine when it belongs to the period associated with the emperor Antoninus Pius, particularly the Roman occupation of Scotland following the advance north in the AD 140s.
An Antonine fort, for example, normally means a fort occupied during this phase.
The most famous Antonine monument is the Antonine Wall.
B
Barrack block
A barrack block was a long building providing accommodation for soldiers.
Roman forts usually contained rows of barracks divided into rooms or suites.
Their arrangement can help archaeologists estimate how many troops were accommodated at a site.
Berm
The berm is the level strip of ground between a defensive rampart or wall and the ditch outside it.
On a plan of a Roman fort or frontier, it often appears simply as an empty space.
It was nevertheless an important part of the defensive system.
Bathhouse
Roman military forts frequently had a bathhouse, sometimes inside the fort but often outside it.
Bathhouses could contain rooms of different temperatures, changing areas and heated floors.
They were important places for washing, exercise and social life.
The surviving bathhouse at Bearsden is one of Scotland’s best-known examples.
See also: Hypocaust
C
Clavicula
A clavicula is a form of defended entrance sometimes found at Roman temporary camps.
Part of the rampart curves around the approach to the gate, forcing anyone entering the camp to follow a controlled route.
Archaeologists distinguish between different forms, including internal and external claviculae.
See also: Titulus
Cohort
A cohort was a Roman military unit.
A legion was divided into cohorts, but many auxiliary infantry units were also organised as independent cohorts.
When inscriptions identify a cohors at a Scottish fort, they may provide valuable evidence about the troops stationed there.
Cropmark
A cropmark is a pattern visible in growing crops caused by buried archaeology.
A buried ditch may retain more moisture, allowing crops above it to grow taller or greener.
A buried stone wall may create shallower, drier soil and stunt growth.
From the air, these differences can reveal the outlines of:
- forts
- marching camps
- roads
- ditches
- buildings
- settlements
Some Roman sites known from cropmarks leave almost no visible trace at ground level.
D
Ditch — fossa
A ditch was one of the basic elements of Roman military defence.
Forts, fortlets, temporary camps and frontier works could all be protected by one or more ditches.
Roman military ditches were frequently V-shaped.
The Latin word fossa is sometimes used in archaeological descriptions.
Distance slab
The Antonine Wall distance slabs are carved and inscribed stones recording sections of frontier construction undertaken by Roman legionaries.
They name the legion responsible and record the length of work completed.
Many are richly decorated with military imagery, Victory figures, legionary symbols and scenes expressing Roman power.
Eighteen are known, making them one of the most remarkable groups of Roman inscriptions from Scotland.
Explore: Antonine Wall Distance Slabs
E
Earthwork
An earthwork is an archaeological feature formed from banks, mounds, ditches or other changes to the ground.
A Roman fort does not need surviving stone walls to remain visible.
Its ramparts and ditches may survive as low earthworks almost 2,000 years after they were constructed.
Extramural
Extramural simply means outside the walls or defences.
An archaeologist might describe a bathhouse, settlement or building outside a Roman fort as extramural.
F
Flavian
Flavian refers to the period of the emperors Vespasian, Titus and Domitian, who ruled between AD 69 and 96.
In Scotland, the term is particularly important because the major Roman advance associated with Agricola took place during this period.
A Flavian fort normally means a fort first constructed or occupied during the late first century AD.
Fort
A Roman fort was a defended military base.
Most forts in Roman Scotland were designed for auxiliary troops rather than an entire legion.
They commonly contained:
- headquarters
- barracks
- a commander’s house
- granaries
- workshops
- roads
- stores
They were protected by ramparts and ditches.
Some Scottish forts were occupied during several separate Roman campaigns.
Explore: Roman Forts in Scotland
Fortlet
A fortlet was a small fortified military post.
It was larger and more substantial than a simple watchtower but much smaller than a normal fort.
Fortlets could house small detachments responsible for observing roads, guarding crossings or controlling movement.
A series of fortlets formed part of the Roman military system along the Antonine Wall.
Explore: Roman Fortlets in Scotland
Fortress
A fortress was much larger than an ordinary Roman fort.
It was intended for a legion numbering several thousand soldiers and therefore contained extensive barracks, headquarters, workshops, granaries and other buildings.
The great unfinished or short-lived legionary fortress at Inchtuthil is the most important Scottish example.
G
Gask Ridge
The Gask Ridge is the modern name given to a remarkable Roman military system in Perthshire.
It includes a Roman road accompanied by a chain of:
- forts
- fortlets
- watchtowers or signal stations
Much of the system dates to the late first century AD and therefore predates both Hadrian’s Wall and the Antonine Wall.
It is sometimes described as one of the earliest Roman frontier systems, although archaeologists have debated whether it is best understood as a true frontier or as a fortified military and communication route.
Explore: The Gask Ridge | Gask Ridge Watchtowers
Geophysical survey
Geophysics allows archaeologists to investigate what may be buried beneath the ground without excavating it.
Different instruments detect variations caused by buried ditches, walls, hearths and other features.
Two common methods are:
Magnetometry
Detects tiny variations in the earth’s magnetic field.
It can be particularly effective at identifying ditches, ovens, pits and areas affected by burning.
Electrical resistance survey
Measures how strongly the soil resists an electrical current.
Stone walls and filled ditches can produce different readings and reveal buried structures.
Geophysics has transformed our understanding of many Roman sites in Scotland.
H
Horreum
A horreum was a Roman granary or store building.
Fort granaries are often recognisable archaeologically because they had raised floors designed to allow air to circulate beneath stored grain and reduce damp.
Large military garrisons required enormous quantities of food, so granaries were essential buildings.
Hypocaust
A hypocaust was a Roman heating system.
The floor was raised on small pillars, allowing hot air from a furnace to circulate underneath. Heated air could sometimes also pass through hollow tiles in the walls.
Hypocaust systems are particularly associated with bathhouses and high-status rooms.
I
Intervallum
The intervallum was the open area between a Roman camp or fort’s defences and its internal buildings or tents.
In a marching camp it created a clear space inside the rampart.
It could provide access around the perimeter and separate tents, animals and equipment from the defensive works.
L
Legion
A legion was one of the major formations of the Roman army.
During the principal Roman campaigns in Scotland, legionaries were involved not only in fighting but also in construction and engineering.
The three legions particularly associated with building the Antonine Wall were:
Legio II Augusta
Legio VI Victrix
Legio XX Valeria Victrix
Legionary fortress
See: Fortress
Lilia
Lilia were small defensive pits placed in groups in front of Roman defences.
The name means “lilies” and refers to their shape.
Some probably contained sharpened stakes.
A famous group of pits discovered near Rough Castle on the Antonine Wall is generally interpreted as Roman defensive lilia.
M
Mansio
A mansio was an official stopping place associated with the Roman road network.
Such establishments could provide accommodation and facilities for officials and travellers using the imperial communications system.
Identifying a building as a mansio archaeologically can be difficult, so the term should be used cautiously unless there is good evidence.
Marching camp
A marching camp was a temporary defended enclosure used by Roman troops while campaigning, travelling or carrying out particular tasks.
The army could construct a camp at the end of a day’s march.
A typical camp might contain:
- a defensive ditch
- an internal rampart
- protected gateways
- rows of tents
- internal streets
- an open intervallum behind the defences
Some were occupied for only a short time.
Because Scotland saw repeated Roman campaigns, hundreds of temporary camps or possible camps have been identified.
Explore: Inside a Roman Marching Camp
Military Way
The Military Way was the Roman road running behind the Antonine Wall and connecting its forts and military installations.
It allowed soldiers, supplies and messages to move along the frontier.
The name should not be confused with Roman roads more generally.
Mortarium
A mortarium was a heavy Roman mixing or grinding bowl.
Its inner surface often contained grit to help process food.
Fragments of mortaria are common archaeological finds and can sometimes help archaeologists date a site or identify trading connections.
O
Occupation phase
Roman sites were often occupied, abandoned, rebuilt and occupied again.
Archaeologists therefore divide their history into phases.
A Scottish fort might, for example, contain:
Flavian occupation → abandonment → Antonine reoccupation
Recognising these phases is essential when reconstructing Roman campaigns in Scotland.
P
Pila
Pila is the plural of pilum, the distinctive heavy throwing spear or javelin carried by Roman legionaries.
Do not confuse this with pila muralia.
Pila muralia
Pila muralia were wooden stakes associated with Roman field defences.
Roman soldiers could carry stakes on campaign and use them as part of the temporary defences of a marching camp.
They are often reconstructed as sharpened wooden stakes forming a barrier along the top of a camp rampart.
Posthole
A posthole is the archaeological trace left where a timber post once stood.
The timber itself may have disappeared completely, but changes in the soil can reveal where it was positioned.
Patterns of postholes can allow archaeologists to reconstruct Roman:
- buildings
- gateways
- towers
- fences
- barracks
At some sites, postholes are almost all that remains of timber structures.
Praetorium
The praetorium was the commander’s residence in a Roman fort.
It was usually a relatively large building and might resemble a Mediterranean courtyard house.
In a temporary military camp, the term can also refer to the area or tent associated with the commander.
Do not confuse it with the principia, the fort’s headquarters building.
Principia
The principia was the headquarters building of a Roman fort.
It normally occupied an important central position.
It could include:
- a courtyard
- administrative rooms
- a large hall
- offices
- the shrine where the unit’s standards were kept
The principia was the administrative and ceremonial heart of the fort.
R
Rampart
The rampart was the defensive bank surrounding a Roman fort, fortlet, camp or frontier.
It might be built from:
- turf
- earth
- timber
- stone
- combinations of these materials
The Antonine Wall itself was principally a turf rampart built on a stone foundation, with a substantial ditch to its north.
RIB — Roman Inscriptions of Britain
RIB stands for Roman Inscriptions of Britain.
It is the standard catalogue used to identify Roman inscriptions from Britain.
An inscription might therefore be referred to as:
RIB 2139
rather than repeatedly using its full description.
RIB numbers appear frequently throughout Romans in Scotland.
Explore: Roman Inscriptions | Primary Sources
Roman road
Roman roads connected forts, frontiers, ports and supply bases.
They were designed for reliable military and administrative movement rather than simply travelling in perfectly straight lines.
Archaeologists can identify Roman roads through surviving earthworks, excavated surfaces, roadside ditches, aerial photography and geophysical survey.
Explore: Roman Roads in Scotland
S
Samian ware
Samian ware is the name commonly used in Britain for fine, glossy red Roman pottery.
It is also called terra sigillata.
Much of the Samian pottery found in Roman Britain was manufactured in large production centres in what are now France and Germany.
Potters sometimes stamped their names onto vessels.
Because production centres, potters and styles can often be dated, Samian ware can be extremely useful to archaeologists.
Scheduled monument
A scheduled monument is an archaeological site given legal protection because of its national importance.
Many Roman forts, camps, roads and frontier remains in Scotland are scheduled monuments.
The term describes their modern protected status, not their Roman function.
Severan
Severan usually refers to the period associated with the emperor Septimius Severus and his dynasty.
In Scotland, it most commonly refers to the major campaigns launched by Severus from AD 208.
A Severan camp or Severan occupation therefore relates to this early third-century phase of Roman activity.
Signal station
See: Watchtower
Small finds
Archaeologists use small finds for individual objects recovered from a site rather than major structural remains.
Examples include:
- brooches
- coins
- tools
- weapons
- jewellery
- gaming pieces
- fittings
- personal objects
Small finds can tell us about the people who occupied a site as well as when it was used.
Stratigraphy
Stratigraphy is the study of archaeological layers and the order in which they were deposited.
In simple terms:
A layer or structure underneath another is usually older than what lies above it.
At complex Roman forts, stratigraphy can reveal repeated episodes of:
construction → occupation → demolition → rebuilding → abandonment
T
Temporary camp
See: Marching camp
Not every temporary camp was necessarily built after a day’s march. Some may have housed troops involved in sieges, construction work, training or longer military operations.
For this reason, archaeologists often prefer the broader term temporary camp.
Terminus ante quem
Latin for “limit before which”.
A terminus ante quem gives the latest possible date by which something must already have happened.
For example, if a building was buried beneath a road securely dated to AD 160, the building must pre-date the road.
Terminus post quem
Latin for “limit after which”.
A terminus post quem gives the earliest possible date something could have happened.
For example, if a sealed archaeological layer contains a coin minted in AD 142:
the layer cannot have been deposited before AD 142.
It does not prove that the layer was deposited in AD 142 — only that it must be AD 142 or later.
This is one of the most useful phrases to understand when reading archaeological reports.
Titulus
A titulus is a short defensive bank or ditch placed in front of the entrance to a Roman temporary camp.
Instead of walking directly through the gate, anyone approaching had to move around the obstacle.
This helped protect what would otherwise have been a vulnerable break in the camp defences.
See also: Clavicula
V
Vallum
This is one of the more confusing Roman archaeological terms.
The Latin word vallum can be associated with a rampart or defensive earthwork.
However, when archaeologists use the Vallum with a capital V in connection with Hadrian’s Wall, they mean something very specific.
The Hadrian’s Wall Vallum is a large earthwork running behind the Wall, consisting principally of a broad central ditch with mounds alongside it.
It is not Hadrian’s Wall itself.
When discussing the Antonine Wall, this site generally uses the clearer English term rampart for the turf Wall.
Vexillation — vexillatio
A vexillation was a detachment of soldiers taken from a larger Roman military unit.
This is particularly important when interpreting inscriptions.
If an inscription says that a detachment of a legion built something, it does not necessarily mean that the entire legion was stationed there.
Roman legionaries were frequently detached for construction and specialist duties.
Vicus
A vicus was a settlement that developed outside or beside a Roman fort.
These settlements could contain:
- houses
- workshops
- shops
- taverns
- craftspeople
- traders
- families and other civilians
The relationship between fort and vicus provides an important reminder that the Roman military presence involved far more people than soldiers alone.
Via decumana
A road running through a Roman fort or camp towards the rear gate, the porta decumana.
Via praetoria
One of the principal internal roads of a Roman fort or camp.
It normally ran from the main forward-facing gate — the porta praetoria — towards the central command area.
Via principalis
The major road crossing a Roman fort or camp from side to side.
It passed through the central area close to the headquarters.
In a marching camp it formed one of the principal axes used to organise the layout.
W
Watchtower
A Roman watchtower was a small military observation post, usually containing a timber tower protected by a ditch and bank.
Watchtowers allowed soldiers to:
- observe movement
- watch roads
- communicate with neighbouring posts
- maintain surveillance between forts and fortlets
Scotland’s best-known group forms part of the Gask Ridge system in Perthshire.
Watchtowers are sometimes called signal stations, although observation may have been at least as important as signalling.
Understanding archaeological plans
When looking at a plan of a Roman fort or camp, remember that archaeologists are often reconstructing buildings that no longer survive above ground.
A line on the plan might represent:
- a surviving stone wall
- a buried foundation
- a ditch
- a row of postholes
- a cropmark
- a geophysical anomaly
Different levels of evidence can therefore appear equally definite on a simplified plan.
Always ask:
What was actually found?
and:
How certain is the interpretation?
That distinction is particularly important in Roman Scotland, where many military sites are known largely from aerial photography or geophysical survey rather than complete excavation.
Archaeological periods you will encounter
Flavian
Late first century AD, particularly the campaigns associated with Agricola.
Hadrianic
Associated with the reign of Hadrian, AD 117–138.
Antonine
Associated with Antoninus Pius and the renewed occupation of Scotland from the AD 140s.
Severan
Associated particularly with the campaigns of Septimius Severus beginning in AD 208.
These labels are convenient archaeological shorthand. They do not always mean that a feature can be dated to an exact year.
Keep exploring
Now that the terminology makes a little more sense, try exploring the evidence itself:
Roman Forts in Scotland
Discover Scotland’s forts by campaign and region.
Roman Fortlets in Scotland
Explore the smaller military posts that helped connect Rome’s military network.
Inside a Roman Marching Camp
See how a temporary Roman camp was organised.
The Antonine Wall
Explore Rome’s most northerly major frontier.
Maps & GIS
See forts, roads, camps and archaeological discoveries in their landscape.
Explore Primary Sources
Investigate inscriptions, ancient writers, archaeology and the evidence behind the story.
A final note
Archaeological terminology changes as research develops, and archaeologists do not always agree about how individual sites should be interpreted.
A “fortlet”, “watchtower” or “frontier” is therefore not simply a label. It is sometimes an interpretation based on the evidence currently available.
That uncertainty is part of archaeology.
See a term on Romans in Scotland that isn’t explained here? This glossary can continue to grow as new subjects are added to the site.
