Returning from exile in Gaul as a Christian, Sigeberht built schools and monasteries and settled Felix as his bishop at Dommoc, and Fursey, Irish monk and missionary, at Cnobheresburg.

Sigeberht shared his rule with Ecgric, possibly a nephew of Raedwald's, but in time left power and entered his monastery of Beodricesworth.

The account of this battle occurring at Blythburgh, where Anna died together with his son Jurmin, and of his burial nearby, appears in the Life of Etheldreda as found in the 12th-century Liber Eliensis.

An accommodation with Mercia was reached by the conversion of Penda's son King Wulfhere and his marriage to Anna's granddaughter Eormenhild, daughter of Seaxburga.

[11][12] These conclusions were dramatically reinforced by the dating of standing ruin of the south wall of the priory church to the 11th-12th centuries, older than the crossing and east works.

The Life of Saint Etheldreda (founder of the abbey of Ely), which forms part of the Liber Eliensis, reports that Anna’s and Jurmin’s remains had been buried at Blythburgh.

During the later 11th and early 12th centuries, Benedictine monasticism centred upon large religious communities in cities, with imposing buildings, powerful abbots and scholars, and considerable affluence.

In contrast there arose a desire to follow a more primitive type of religious life, as canons regular in smaller, secluded communities.

In 1171 the Precentor of Blythburgh (whose office implies a fully organized community) was chosen to become the first prior of Ranulf de Glanvill's larger Augustinian house for 36 canons at Butley Priory (1171).

[25] Gilbert satisfied his very influential patrons: he continued at Butley until his death around 1195, playing his part in the exchange of endowments with Ranulph's Premonstratensian foundation at Leiston Abbey in 1183 (then located at Minsmere),[26] assisting in the foundation of Leiston's daughter house at Langdon Abbey in Kent in 1192,[27] and taking on the governance of Ranulf's leper hospital at West Somerton in Norfolk:[28][29] The lordship of Blythburgh is traced from King Stephen's grant to John son of Robert de Chesney, and after his death to his brother William in 1157.

Hugh and his brother Stephen both dying in 1263, Robert fitzRoger, a descendant of Margaret de Chesney's second marriage, became lord of Blythburgh until 1310, and in 1278 confirmed all the grants to the priory made by his predecessors.

His son John fitzRobert, also called de Clavering, was lord of Blythburgh from 1310 to 1332,[33] and was granted in Suffolk the Hundreds of Blything and Waineford[34] in 1313, for life.

Its close neighbour, Thorington church (beside the Bramfield brook descending to the Blyth), the advowson of which was granted to the priory by the rector of St John of Dunwich,[38] was appropriated in 1347.

[39] The church of Claxton, Norfolk, confirmed by William de Kerdeston, was evidently granted to Blythburgh in connection with fitzRoger's foundation at Langley Abbey in the adjoining parish.

[45] These, taken with the Cartulary and the Taxatio, reveal an expected concentration of holdings in Bulcamp and the neighbouring parishes of Blythford, Wenhaston, Holton St Peter, Henham, Sotherton and Westhall, in the Blyth hinterland.

The eastern end of the nave now opened into a central tower crossing supported on four large corner piers, one of which (the north-western) still survives as a rubble core to the height of some 7.7 metres.

A solitary coffined grave lay aligned on the central axis of the presbytery towards its eastern end, a ceremonial position for a burial of importance inside the church structure.

These openings must have given into a covered space, and doorways in the western walls of the transepts suggest outer structures (but not aisles) both north and south of the nave.

On the north side of the nave the ground level was noticeably lower than the interior floor-level, and a flight of steps went down from the transept's west doorway into a walkway or ambulatory about 3 metres wide.

A large hole in the pier fabric suggests the fixing at this corner of a timber transom or tie beam to support the walkway roof structure.

"[53] The Hopton interest in Blythburgh was inherited from their ancestor Sir Robert de Swyllington (died 1391), a South Yorkshire dignitary who owned lands here.

John (who had no knighthood) died in 1478, having in 1451 received licence to establish the "Hopton Chaunterye" in Holy Trinity Church, Blythburgh, for the good estate of himself and for the soul of his late wife Margaret.

[73] An illustration of the priory by Francis Grose, engraved 1772, shows a large but incoherent mass of masonry, standing to a good height, with a number of round arches surviving and the remains of openings in the superstructure.

"[74] The engraving of a drawing by T. Higham, c. 1800, still shows two parallel sections of wall, probably of the priory church, with arched openings below and broken window embrasures above.

Excavations were made upon the site, and beneath the debris were discovered ancient coins, keys, Encaustic tiles bearing the signs of the Zodiac, etc., of great interest.

During the excavations mentioned several human skeletons were found scattered upon the pavement of the Conventual Church, as if some resistance had been made by the inmates at the time of its suppression, and the buildings rased to the ground over their heads, and thus got entombed beneath the rubbish.

"[77]Following the Time Team investigation of 2008,[78] since 2009 further, more prolonged and systematic campaigns of exploration and conservation, led by Stuart Boulter and Bob Carr of the Suffolk County Council Archaeological Service in connection with English Heritage and the owners of the site, have rediscovered the former remains of the large priory church with central crossing and transepts, and a cloister on the north side of the church.

[80] The owners of the site, who have contributed to the costs of (and enthusiasm for) these campaigns, have created an informative website describing the journey of rediscovery of the remains and their investigation.