EAA 87, 1999: Excavations in Thetford, North of the River, 1989–90, by Phil Andrews and Kenneth Penn

Three major excavations and other work in Thetford reveal settlement north of the river by AD1000, within a semi-circular defensive enclosure which probably pre-dates that south of the river, but was initially little more than a bridgehead.
Occupation peaked in the 11th and 12th centuries, with a shift of people to the north bank, followed by medieval decline.
The bones represent a range of domestic animals, dominated by sheep kept for wool, cattle for meat and dairy products, and then pigs.
Some stray Middle Saxon finds may hint at re-use of the Iron Age fort as an exchange/market centre.

Full reference:
Phil Andrews , Kenneth Penn, 1999. 'Excavations in Thetford, North of the River, 1989–90', East Anglian Archaeology 87