Perhaps the best known of all the of Roman fleets, it was created for the invasion of Britain and saw a long and interesting history out on the fringes of Empire.

The Classis Britannica was created in 41 AD, in the Port of Gesoriacum - (modern Boulogne-sur-Mer). This fleet's purpose was to provide support for the 43 AD invasion of Britain. Gesoriacum, the original base was the port of embarkation of the invasion force which was 'led' by Emperor Claudius (from behind in Rome) and General Aulus Plautius (from the front in Britain). After the successful crossing of the Occeanus Britannicus, the English Channel, The 40,000 men of the legions made landings on the Kent coast at Richborough,¹ Lympne² and Dover,³ establishing a beech head of about 45 miles wide. Soon after they moved east andestablished a supply base at Noviomagus (modern Bosham) Sussex. The fleet was again in action supporting the crossing of the Thames, and providing an escort for Emperor Claudius in 46 AD when he visited Britain, transporting his Praetorian Guard, and the elephants for his triumphal entry into Camulodunum, modern Colchester.

Between the years 84 - 86 AD, home port was transferred to either Rutupiae (modern Richborough) or Dubris (modern Dover) the most probable of the two ports.⁴ The British fleet started to establish bases around Britain such as Portus Adurni - Portchester, Anderida - Pevensey, Portus Lemanis - Lympne and a fleet anchorage at each end of Hadrian's Wall at Maia - Bowness and Arbeia - South Shields. In the push north of 83 AD, the fleet carried out raids along the eastern coast of Scotland in support of the advancing legions. The fleet also accomplished the circumnavigation of Britain, discovering the Orkneys in the process. During the reign of Constantine I this system became an independent command referred to as the Litus Sxonicum the Saxon shore defences, with bases located at shore forts around the coast. The commander of the Litus Sxonicum was given the title of Comes Litoris Saxonice Britanniam, or Comes Litoris Saxonici Britannia both ment Count of the Saxon Shore.

The province of Britain was isolated enough that in 286 AD, a commander of the Classis Britannica, named Carausius, to break with Rome and declare himself emperor of Britannia and northern Belgic Gaul. This was when he was accused of conspiracy with pirates from Germany and France.⁵ It is an indication of the formidable strength of the British fleet that it defeated a combined fleet from the bases in Germany France that was sent against it. In 296 AD the revolt was ended when Carausius was assassinated by a subordinate named Allectus this allowed the opportunity for an imperial force to make a landing. By Britain was regained by Constantius in 296-7 AD, and was fully pacified and reinstated in the empire by 300 AD.

The number of forts and their locations gives us a good indication of the threats to the province that existed at the time. The main dangers were to the section of the east coast from Hampshire to the eastern end of Hadrian’s wall, the bases listed are as follows.

Classis Britannica and the Saxon Shore Forts

These bases are known as the Saxon shore forts, there is a distinction between the Classis Britannica and the Saxon shore forts. This distinction can be explained by examining the development of the role of the of the Classis Britannica during the time the Romans held the province of Britain.

The Classis Britannica was the naval and military force that was responsible for the security of the entire coastline of the Roman occupied province of Britannia. The Classis Britannica was supported by the land based forces of the legions from the inland forts throughout the province. This force focused its defensive efforts on the east coast owing to the activity of raiders from mainland Europe. The division between the east and western coasts became such that the east coast became known as the Wash Solent Limes⁶. A Roman limes is a unified defensive system situated on a frontier, performing the same duty as Hadrian’s wall in the north, there was however no need for a wall as the coast served that purpose admirably. There were also nine strong forts at strategic points along the coast these forts were listed in an official Imperial document known as the Notitia Dignitatum. They developed into the Saxon Shore Fort system, the bases located from Hampshire to the eastern end of Hadrian’s wall working south to north the first fort was,

Portus Adurni -
Portchester Castle. The garrisons mentioned in the Notitia Dignitatum were the Numerus Exploratorum and the Numerus Exploratorum Habitanco or The Company of Scouts from Habitancum both units were auxiliary scouts.
Working north along the coast the next fort in the chain was,Anderida – Pevensey.
The original garrison appears to have been the Numerus Abulcorum a company of auxiliaries from Spain.Portus Lemanis – Lympne.
From the fourth century the garrison of the fort was the Numerus Turnacensium.Dubris – Dover
The garrison was provided by the Milites Tungrecani or the men of the Tungrecani.Rutupiae – Richborough.
The garrison was sections of Legio II Augusta the Second Augustan Legion.Regulbium – Reculver.
From the third century it garrisoned by the Cohors I Baetasiorum auxiliaries recruited in the Rhineland. This unit was posted here from Maryport on the Cumbrian coast.Othona – Bradwell-on-Sea. The garrison was the Numerus Fortensium or the Company of Brave Men.Gariannonum – Burgh Castle.
The garrison was the Equites Stablesiani Gariannoneses or Horsemen from the Stables at Gariannum.Branodunum – Brancaster.
The Celtic name of which was Fort of Bran. The original garrison appears to have been the cohors I Aquitanorum a company of auxiliary infantry from the area north of the Pyrenees and later Equites Dalmatae Brandodunenses. A unit of auxiliary horse from Dalmatia, the unit took the title Brandodunenses from the name of the fort.

The term Numerus refers to an army unit of 200 to 400 men normally auxiliary, the number varied depending upon the duties of the unit.

There were also forts located at Bradwell, Caister and Walton situated at the mouths of the Rivers Orwell, Deben and Stour off Felixstowe, both forts are now lost due to coastal erosion. Further forts were at Carisbrooke and possibly at Bembridge on the Isle of Wight as this provides a fine sheltered anchorage on the eastern side of the island. There was also a base at Clausentum near Bittern on the outskirts of Southampton, Cardiff, Holyhead and Topsham.




On the vulnerable northwest coast there is evidence of a chain of five watchtowers located at Filey, Scarborough, Ravenscar, Goldsborough and Huntclif this coastal defence relied upon the deployment of forces by road. Troops from Lindum, modern Lincoln could reach the area on Ermine Street via the Roman ferry⁷ across the Humber estuary from Wintringham to Brough on Humber. All the forts appear to have been linked by signal stations and watchtowers to local garrisons and legionary garrisons such as the ones at Linum and Ebuacum modern York and Corstopitum modern Stangate located on Hadrian’s Wall.

The forts in Britain were supported by a chain of forts along the coast of France from Nantes to Oudenburk in Belgium, this included a base on Alderney on the Channel Islands. The bases on mainland Europe were also listed in the Notitia Dignitatum and are as follows.

Manatias - Nantes. The garrison was the Milites Superventores, this was an auxiliary unit of light cavalry.Benetis – Vannes. The garrison was the Milites Mauri Beneti this was a mixed unit of light auxiliary cavalry.Blabia – Hennebont. The garrison was the Milites Carronensii.Osismis – Brest. The garrison was the Milites Martensii Mauri Osismiaci, this was probably a unit of light auxiliary cavalry.Aletum – Saint-Malo. The garrison was the Milites Martensii.Abricantis – Avranches
The garrison listed was the Milites Dalmati a unit from modern Dalmatia.Constantia – Coutances. The garrison mentioned was the Legio I Flavia Gallicana Constantia or Reliable Flavian Legion of Gaul. This was an infantry unit with auxiliary cavalry support.Rotomagus – Rouen. The garrison was the milites Ursariensii.Grannona – Port-en-Bessin. The garrison was the Cohors Prima Nova Armoricana.

All units listed as the garrison in the forts were listed in official documents such as the Notitia Dignitatum.

Although not listed in the Notitia Dignitatum the final fort in the chain appears to have been Oudenburk in Belgium. There is little remaining evidence however it is reasonable to expect that the forts would have been connected by signal stations and watchtowers with supporting garrisons as in Britain.

Possible locations of other Bases

The Classis Britannica was likely to have had more bases then those listed in the Notitia Dignitatum. There is remaining evidence of some bases, and the locations of other remaining forts and settlements, together with the geography of the British coast it is possible to suggest the most likely locations bases, these may have been at the following places.

The West Coast

Bowness on Solway is guarded by a fort located at Bowness (Maia) this is the most easterly of the forts on Hadrian’s wall. A possible anchorage ships has been recorded in the area. It is probable that the fort at Bowness opreated a system of mutual support to the other base on the Solway Firth,which was the fort at Kirkbride (Portus Trucculensis). This installation was large enough to be a base, and was large enough to provide a possible base or anchorage for ships supporting any advance north of Hadrian's Wall.

The estuary of the River Ellen which was guarded by the fort at Aluna, modern Maryport. A possible anchorage in the estuary of the River.

The estuary of the rivers Esk, Mite and Irt there was a settlement at Ravenglass (Glannoventa). This settlement was important enough to be guarded by a Legionary fort with a garrison of 1,500 horse and foot troops. As Glannoventa also means The Shore Market this indicates the settlement was also a trade centre. Although not listed in the Notitia Dignitatum evidence suggests this was a base.

The estuary of the River Dee, was guarded by a Legionary fort garrisoned by the Legio XX Valeria Victrix at Chester (Deva) this was a large city as important as London and vulnerable to raiding parties from the Isle of Man and Ireland. A probable navy base and port.
The estuary of the River Severn, guarded by a forts constructed at Cardiff and Caerleon (Iscia Augusta). On the river Usk a Legionary fort was constructed by the Legio II Augusta. And the settlement and port of Abona modern Bristol was also established. The estuary was the access to the ports at Caerleon and Bristol on the mouth of the River Avon and given the nature of the settlements and trade activity in the area most unlikely that a base of some sort or anchorage would not have been established.

There is a Roman site that has been lost to the sea located on the north bank Camel estuary near Rock. There is speculation that this was a west coast equivalent of a Saxon Shore Fort. There is no absolute proof of this as the site has been buried beneath the sands of the estuary.

The Channel And East Coast

Exeter (Isca Dumnoniorum) Dumnonii Tribal Capital, is situated on the river Exe just three miles from the major port of Topsham. The port of Topsham was originally intended to provide a supply port for the II legion Augusta based in Exeter. The port was situated on the Fosse Way which ran north from Exeter and provided the settlement with a driect link to London and Lincoln. Owing to the importance of this settlement it is inconceivable that this was at least a possible anchorage, probably a base linked to the legionary garrison.Poole was established by the II legion Augusta before they moved on to Exeter. This was a fort and a Roman port that traded with Gaul, the exports were local sea salt Shale and Limestone. If you look at a map you will see this is a wonderful natural harbour and a very strong candidate for a fleet anchorage.Harwich on the estuaries of the Stour and Orwell rivers these were a major route inland via the rivers in the area. This indicates there was considerable activity on the waterways in the area. A legionary fort, part of the coast stood at Walton on the northern shore of the estuary. This was an important settlement that would have needed protection from raiders and would have probably been a fleet anchorage.



The Humber estuary was the site of a settlement on the northern shore 7 miles to the west of Hull. This site was Peturia there may have been a port sited on the Humber to serve this important settlement. There is a reasonable chance that this may have been the site of a fleet base or anchorage.Whitby (Dictium) was listed in the Notitia Dignitatum as the site of a Roman (signal) station. There is a post Roman referance to Whitby as Streanæshealh or lighthouse bay. This could indicate the signal station was still standing or in use. There was also a fort recorded in the area. It is reasonable to conclude that a base of some sort could have been established.

The Tees estuary and the area around Catcote overlooking the estuary has evidenced of both bronze age and Roman settlement. The area has excellent farming land and after the completion of Hadrian’s wall trade in the area developed. The settlement developed into an important (if minor) trading port it was possible there was an anchorage or a base linked to a garrison in the area possible anchorage.