Thetford, a market-town on the border of Norfolk and Suffolk, at the Thet's confluence with the Little Ouse, 31 miles SW. of Norwich and 12 N. of Bury St Edmunds. Doubtfully identified with the Roman Sitomagus, it was the capital of Saxon East Anglia, the seat from 1070 of a bishopric, transferred to Norwich in 1094 (since 1894 it again gives title to a suffragan bishop). It suffered much from the Danes between 870 and 1010; in Edward III.'s time it had eight monasteries and twenty churches (now only three). The steep Castle Hill, 100 feet high and 260 yards in circumference, is one of the largest earthworks in the kingdom; and there are remains of Bigod's Cluniac priory (1104). The grammar-school (1566) was rebuilt in 1879. The industries include brewing, tanning, and farming machinery; and there is some trade by barges on the Ouse. 'Honest' Tom Martin, the antiquary, and Tom Paine were natives. Incorporated in 1573, Thetford returned two members till 1867; it has a suffragan bishop under Norwich (1894). Pop. 4700. See works by Martin (1779) and Hunt (1870).