The Cistercian Abbey of the Blessed Virgin Mary at Sibton was colonized by a group of monks from the Abbey of Warden in Bedfordshire in the year 1150, which house was in turn founded from the Yorkshire Abbey of Rievaulx.
The site is by the banks of the River Yox, which at this point is a relatively small river in a broad, shallow glacial valley cutting through the eastern edge of the Suffolk clay plateau. The site is in private ownership and there is little to be seen of the remains of the abbey from the road.

The founder was William de Cadomo (alias William Fitz Robert), third son of a local Norman lord, Robert son of Walter, who was reputed to be the brother of William Malet, tenant in chief of the manor of Sibton at the time of the Domesday survey. Robert married Sibilla, daughter and heir of Ralph de Cheyney, and their descendants took the maternal name. A subsequent patroness of the Abbey was Margaret de Cressy, nee Cheyney, daughter and heir of William, and one by whom the original grants were substantially augmented.

Sibton was the only Cistercian house in Suffolk and a sister house of Sawtry in Huntingdonshire (1149) and Tilty in Essex (1153). It had wide possessions in East Suffolk and Norfolk.

A description of grange system has come from a study of the abbeys surviving manuscripts, owned by the local Scrivenor family. carried out by A.H. Denney. In particular, this research has revealed that the monks were in the main stream of national agrarian developments.

At the dissolution its annual income was valued at £250, £58 more than Tintern. With no large buildings to maintain this is a measure of the prosperity of four centuries of mixed farming in Suffolk.

The advowson of the church of Westleton was given to the abbey in I272, and it was appropriated in 1332.

The taxation roll of 1291 shows that this abbey held lands or rents in ten parishes of the city of Norwich, and in twelve parishes of the county of Norfolk. There were also considerable land in upwards of twenty-five Suffolk parishes. The religious endowments consisted of the rectory of Sibton with the chapel of Peasenhall, and portions from four other churches. The total annual income of the abbey was £144 3s. 4d.

The most important MS. relative to this abbey is the chartulary or register (Arundel 221) formerly in the Earl of Arundel's collection, afterwards in the library of the Royal Society, but transferred to the British Museum in 1831. It was drawn up towards the end of the fourteenth century, and contains 153 parchment folios.From fol. 32 to fol. 143 is a chartulary proper; the charter transcripts are followed by a series of papal bulls granted to the abbey of Sibton, twenty-two in number, ranging from Alexander III, lido, to Innocent IV, 1254. The earlier part of the volume contains a variety of entries, such as copies of Magna Charta and the Forest Charter, the names of the kings of England down to Edward III, list of the towns in Blything hundred, and various pleas and inquisitions relative to the abbey in the reigns of Edward III and Richard II. Of this chartulary there are several transcripts. A portion, on paper in an Elizabethan hand, appears in Cott. MS. Vitel. fol. xii. Add. MS. 8172 (vol. v. of Jermyn's Suffolk Collections) is entirely occupied with Sibton parish, and most of it with transcripts of the abbey charters and evidences. Add. MS. 19082 (part of Davy's Suffolk Collections) concerns Sibton from fol. i to 249, mainly about the abbey. Most of Davy's transcripts correspond with Arundel 221, but others, with some variants, are taken from a chartulary and two bursar's account books of the fifteenth century, then in possession of the Bishop of Salisbury. Rawlinson MS. B. 419, of the Bodleian, is a transcript of Arundel 221. A further chartulary, cited by Jermyn and Davy, in the possession of Mr. Scrivener of Sibton, appears also to correspond with the Arundel register. Other miscellaneous extracts are to be found in the Dodsworth MSS. of the Bodleian, and in the Harley Collection (2044 and 2101) of the British Museum.

The Dissolution
Henry, abbot of Sibton, was summoned to attend convocation in 1529. An undated memorandum among the State Papers, but clearly of the year 1536, gives the names of the religious of this house, namely, William Flatbury, abbot; Robert Sabyn (alias Bongay), prior; and six other monks. It is noted that the vicar-general was to be asked to commission some person to take the abbot's resignation, with capacity to change his habit, and to take two benefices with cure without residence, and a licence for the same from the chancellor. The abbot was willing to purchase these privileges. Also for the monks, save Prior Sabyn and another of the name of John Fawkon, all desired ' capacities,' and to take a benefice each with cure.

The value of this house being well over £200 a year, it would not have fallen for another two years; but the recently-appointed abbot, William Flatbury, had apparently been put in through the influence of the Duke of Norfolk, and with the connivance of Cromwell, on purpose to bring about a speedy surrender. At all events the abbot and convent sold their house and possessions to Thomas, duke of Norfolk, some time in 1536, and this action was confirmed by Act of Parliament in 1539. In the duke's annual receipts for 1538 entry is made of 'Sipton £200', whereof to the quondam (abbot) and other monks £72.10s' It therefore appears that all the monks of this house obtained a pension.

The impression of the fourteenth-century seal attached to a charter of 1406 shows the Blessed Virgin under a pinnacled and crocketed niche; on each side is a flowering branch, as well as a star on one side and a crescent on the other; in the base under an arch is a lion's face, a possible allusion to the arms of the founder's family.

Excursion and lecture (1892)
Local estate of abbey