Burgh Castle (Gariannonum?) Roman Fort

Saxon Shore Fort

The Burgh Roman fort is located on the east bank of the River Waveney in Norfolk, England.

Built sometime after AD 260, the Burgh Castle fort lies on a raised tongue of land on the eastern edge of the Norfolk Broads, beside the south shore of the Breydon Water, just west of the modern seaside town of Great Yarmouth. Its flint and tile walls enclose an area of almost 6 acres (2.4 ha) and still survive to a height of 4 metres on all sides bar the west, which has been lost to erosion by the river. The east-west dimension is a fairly uniform 330 ft. (c.100 m) within the ramparts, and although the east and west sides abut the northern side at right-angles, the east side is some 50 ft. (c.15 m) shorter than the west, which measures around 660 ft (c.200 m) in length, thus the south-east angle is decidedly obtuse, the south-west likewise acute.

It was probably a Saxon Shore fort and called Gariannonum, Gariannum or Gariannvm, although it could also have meant the Roman fort at Caister-on-Sea.

The Defences of Burgh Roman Fort

Walls of Burgh Roman Fort

The Walls surround an area about 2.4 hectares 6 acres in extent. It is a quadrilateral whose longer sides are parallel, while the shorter sides are not ; the west or longest side has been destroyed by the river, but its foundations have been located. The walls of the fort were around 3.5 metres (11 ft) wide at the base and taper to 1.5 metres (5 ft) at their full height of around 4.5 metres (15 ft).

The walls were faced with flint, with triple bonding-courses of tile; there may have been an earth bank behind them.

Over the centuries the walls have been plundered for building material, exposing the mortared flint rubble core, but they were originally faced inside and out with cut flint and tile in alternating bands. A well-preserved stretch of this facing survives along the outside of the south wall.

Projecting Towers or Bastions of Burgh Roman Fort

They were further fortified, at a late stage in the construction, by projecting towers or bastions. The bastions have  a flat top with a circular sinking or hole in the middle. The hole was either a mechanism to mount or anchor the ballista or catapults, or were used to support timber watchtowers along the top of the wall. This  feature is clearly visible on the bastion that has fallen outward from the south wall. The bastions only begin to be bonded into the walls 7 or 8 feet above the ground; conceivably they may have been added to the plan after building was begun.

The Gates of Burgh Roman Fort

There is a gate in the middle of each remaining wall – the east gate 11 feet 8 inches wide, the other two mere posterns.

The Garrison of Burgh Castle

The Burgh Castle fort was large enough for between 500 and 1000 foot soldiers, or up to 500 mounted soldiers and their horses. Burgh Castle was garrisoned by Equites Stablesiani, a class of cavalry in the Late Roman army. The remains of an iron cavalry helmet were found at the site, similar to helmets found in Holland and Romania dating from the 300s AD.

The Burgh Castle Entry in the Notitia Dignitatum

There is scant epigraphic evidence from Gariannum, and the only classical mention of the fort occurs in the Notitia Dignitatum of the 4th/5th century. The Burgh Castle entry in this document occurs between Branodunum (Brancaster, Norfolk) and Regulbium (Reculver, Kent).

Praepositus equitum stablesianorum Gariannonensium, Gariannonor

“The commander of the Horsemen of the Gariannum Stables at Gariannum.”

(The Notitia Dignitatum xxviii.17; 4th/5th C.)

Classical references to Burgh Castle

The Burgh Castle fort is not mentioned in the second century geographical work by Ptolemy, which is not surprising since the Saxon shore fort was not built until the fourth century. The River Yare does appear, however, and is named the Gariennus Flumen, between the Metaris Aestuarium (the Wash) to the north and an unnamed promontory to the south. The name Gariannonum has been thought to derive from a Celtic root meaning “babbling river,” which may refer to the River Yare at Burgh Castle, although the derivation is uncertain.

Roman Roads near Burgh Castle

There are no known Roman roads to/from Gariannum and it is possible, indeed likely, that the fort was supplied by sea. There was further inland communication via the Gariannus Fluvius (River Yare) to Venta Icenorum (Caistor by Norwich) and via the River Bure to the settlement at Brampton. There is a discussion of the possible overland routes in the entry for the settlement at Caister on Sea, which lay around seven miles to the north, and with which some sea-borne communication must have been maintained.

References for Gariannvm

  • The Archaeology of Roman Britain by R.G. Collingwood (Methuen, London, 1930);
  • Air Reconnaissance of Southern Britain by J.K. St. Joseph in J.R.S. xliii (1953) pp.81-97;
  • The Roman Shore Forts – Coastal Defences of Southern Britain by Andrew Pearson (Tempus, Stroud, 2002);

Map References for Gariannvm

NGRef: TG470046 OSMap: LR134

Sites near Burgh Castle (Gariannonum?) Roman Fort

Visiting Burgh Castle (Gariannonum?) Roman Fort


Daylight Hours



Address: Burgh Castle Fort High Road Burgh Castle Great Yarmouth NR31 9QQ