Fort and Saxon Shore Fort
Gariannonum, Gariannum or Gariannvm, was a Saxon Shore fort 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.
Burgh Castle (Suffolk ; Fig. 11b) is about 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 still stand 15 to 16 feet high, and this seems to have been their original height apart from a parapet ; for the bastions have at this height a flat top with a circular sinking in the middle, showing where a ballista has been mounted. The walls, above all offsets, are 8 feet thick, and faced with flint, with triple bonding-courses of tile; there may have been an earth bank behind them. The corners are rounded, and 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 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.” (Collingwood, p.49)
Classical references to Gariannonum Fort
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.
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).
“The commander of the Horsemen of the Gariannum Stables at Gariannum.”
Roman Roads near Gariannvm
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