- Halton ChestersOnnum
The Wall between Rudchester and this fort at Onnum has been virtually wiped out. As at Rudchester destruction of the Wall was heavy. The difference between random destruction and the devastation here is that this was sanctioned by the government for the building of the Military Way. In the book "The Roman Wall - A Comprehensive History and Guide" by Frank Graham and published in 1979 it is noted as follows: ‘The Reverend William Stukeley in Carausius (1757-9) was incensed at the destruction wrought by "..these senseless animals" as he called them’!
South Wall of Fort
Just like Rudchester this fort was run down from the 270’s AD to the 370’s AD. It covers an area of some five acres and again, as in other forts, the modern main road goes through the middle of it. Watling Street traverses the fort in the valley immediately below and is guarded by the fort which was only constructed after the completion of the curtain wall and ditch. The ditch was in-filled and became the street that connected the east and west gates in the interior of the fort.
An unusual discovery was made with this fort in that an extension was built onto it at the south western side and thus changed its usual playing card style shape (the normal shape usually for a Roman fort) to a peculiar L shape. A second unusual discovery, made in 1827, was that of a bath-house inside the fort grounds. It was considered to be of the late fourth century and these are rare inside forts. An extensive vicus has been found too which runs a few hundred yards south of the fort and the suggestion has been made that the road from the south gate ran to Dere Street which is north of Corbridge (Corstopitum).
The site has been noted for its many inscriptions and sculptures etc and in 1803 a huge gold signet ring was found with an engraving of a female on an artificial blue stone. It was found in the northern area of the fort. The ring itself could well have belonged to one of the officers probably because of his entitlement to wear such a ring. The stone has now been lost, thought stolen.
Garrisons known at on StreetMap 
| Era | Garrison |
|---|---|
| Hadrian | cohors quingenaria equitata ? |
| Marcus_Aurelius | no evidence |
| 3rd_Century | ala Sabiniana |
| Notitia_Dignitatum | ala Sabiniana † |
| 1st_Note | The fort was run down between the 270’s AD to the 370’s AD but the unit apparently survived in name at least. There is an inscription of it from the fort (RIB 1433) which is apparently third century. |