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Norman Thetford

Thetford builds a great cathedral, yet the town’s economic fortunes wane

During the 11th and 12th centuries, after its Late Saxon heyday, Thetford faced a period of economic decline. However, the conquest of 1066 and the Norman dynasty founded by William the Conqueror had an important impact on Thetford: the town’s largest and most impressive medieval sites were created by the Normans.

The Domesday survey of 1086 recorded nearly 1,000 burgesses living in Thetford. Although it is very difficult to work out full population figures from Domesday data, it has been suggested that the population of Thetford at the Conquest may have been around 4,500. This meant that Thetford was one of a handful of similar towns in England, on a par with Norwich, Oxford, Lincoln and York.

In 1071 the Bishop of East Anglia, Herfast, who had been newly appointed by William I, moved the epicopal see of East Anglia to Thetford, using the existing church of St Mary the Great as a cathedral. Herfast then built a new parish church, Holy Trinity, to replace St Mary. Herfast began to acquire wealthy manors and estates for the bishopric, and Domesday Book records the Bishop of Thetford, then William Beaufo, as holding more than 70 manors across Norfolk. In 1094 the diocese was moved to Norwich, and the new bishop, Herbert de Losinga, began the construction of Norwich Cathedral.

Three major landowners were recorded in the Domesday Book in Thetford: the King, William the Conqueror, the Bishop, William Beaufo, and Roger Bigod. The Domesday survey suggests that by 1086 there were only 3,600 people living in Thetford – a decline of nearly 1,000 people over the space of just 20 years. One of the reasons behind this decline was the rise in the fortunes of Bury St Edmunds, where the Abbot was granted extensive privileges over the surrounding area, including the suppression of markets outside Bury. King’s Lynn was also growing more prosperous during this period, so the importance of Thetford as a river port diminished.

Roger Bigod

Roger Bigod was to have a profound influence on the landscape of Thetford. He arrived in England with William the Conqueror. The Domesday Book records that he owned a large amount of land in East Anglia, and he chose to make his base at Thetford.

In 1067-9 a castle was constructed in the ramparts of the Iron Age hill fort. A motte (artificial mound) and bailey was constructed at one end. The scale of the motte is enormous – at 80m high it is the second largest in England. The size of the earthworks suggests that the castle was always intended to be a base of some importance in a strategically important setting. In 1173 Thetford castle was destroyed by Henry II.

Bigod also founded the Priory of St Mary in 1104, which became the largest and most important religious house in Thetford. Bigod had wanted to be buried in the Priory at Thetford, but the bishop made sure that his body was taken to Norwich Cathedral instead. Bigod constructed large castles at Bungay and Framlingham, both in Suffolk

Thetford Priory

Founded in 1104 by Norman nobleman, Roger Bigod – a close associate of William the Conqueror and lord of the manor of Thetford, the Priory was built on a magnificent scale in the rich architectural style typical of the Cluniac order.

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Substantial visible remains open to the public.

Thetford Castle

Known as Castle Hill it was originally a motte and bailey construction and stands close to what was, and still is, an important crossing of the rivers Thet and Ouse. Excavations revealed evidence that it was built on a former Iron Age hillfort immediately after the Norman Conquest in the period 1067 – 1069.

At the time of the Domesday survey, Thetford was among the six largest and most populous towns in the country and this motte was both a strategic military base and a sign of Norman authority.

To construct the huge motte (the mound) thousands of tons of earth, chalk and flint were excavated with hand tools and then moved using bags, barrows, sledges and tubs – local labour providing the workforce. On top of the mound were wooden buildings and a stockade.

The hill is approximately 25 metres tall and is the second largest manmade earthworks of its kind in the country.

The pipe roll (exchequer record) of 1173 records the destruction of a castle, although it is possible that this reference is to Red Castle.

Red Castle

The ringwork castle was constructed in around 1146, although excavations revealed that the site has a long history of occupation dating back to the Roman period.  Red Castle was sited to control the entrance to the town from the west, and the ford across the river at that location.

  • 1065
    Estimated population of 4,500
  • 1067-9
    Castle constructed within the ramparts of the Iron Age fort
  • 1071
    Episcopal see of East Anglia moved to Thetford
  • 1086
    Population reduced to 3,600
  • 1094
    Diocese moved to Norwich1104 – Roger Bigod founds the Priory of St Mary
  • 1173
    Thetford Castle destroyed by Henry II