- FortsCastellum

Segedunum Fort Layout mid-late 2ndC AD
Segedunum Fort Layout mid-late 2ndC AD

Hadrian’s Wall was built with a series of milecastles and turrets before the forts were added later. When they were added the forts behind the Wall on the Stanegate (Corstopitum and Luguvalium for example) were not entirely abandoned. They remained as supply forts for example. Most of the forts followed a general Roman pattern of being built to a shape reminiscent of our modern day playing card. Double portal gates would be included on all sides to allow quick entry and exit points and each corner would have a watch tower as would either side of the gates. The fort would usually be surrounded by a ditch and two roads would cross each other inside the fort and would be aligned to the gateways.


Buildings inside the fort would normally consist of: a Commanding Officer’s House, Headquarters Building, Infantry Barrack Blocks, Cavalry Barrack Blocks (although some contained either one or the other or both), at least one granary, possibly a hospital and several water tanks. Latrines would also be found inside a fort although the Commanding Officer would have his own private latrine and bath. He would entertain guests and officials alike in his house which was made up of a central courtyard with several rooms around the perimiter. The Headquarters Building would be where the Standards of the army were kept. This would be above a strongroom which stored the soldier’s pay and savings being guarded 24 hours a day.


At Segedunum there was an extra building that is generally accepted as a forehall. At present there is no solid evidence as to the purpose of this building although it has been mooted that it could have been used as a drill hall though the size does not lend itself well to this theory although it is better than some other ideas. Typically, a fort could house several hundred men but just to allow you to see what sort of numbers we are talking about I will use Segedunum here as a guide simply because it is the most excavated fort in the Roman Empire. This fort had 600 men stationed inside, 480 infantry and 120 cavalry units. The cavalry blocks were to the southern end of the fort while the infantry were to the north and south. Not all the men would be stationed at the fort at any one time as patrols away from the fort would be required throughout the day. On the diagram, reproduced with permission from the official Segedunum Guide Book written by former curator W. B. Griffiths, you can follow the design as I have numbered each building and supplied a key to help identify them. It is suggested through epigraphic evidence that three wholly cavalry units were based on the Wall at Benwell (possibly), Chesters and Stanwix while three wholly infantry units were based at Housesteads, Great Chesters and Birdoswald. The other forts would therefore have mixed cavalry and infantry units.

Fort Intervals

The forts would be spaced out at 7.3 mile intervals if the original plan had stayed in effect. However, this was impractical and we see distances range from 6.3 to 9.3 miles which allowed for forts near river crossings at Chesters, Birdoswald and Stanwix. It would have been preferable if all forts had sat astride the Wall but again impracticability’s forced some to be built adjoining or one sitting right next to it but not adjoining.