[2] The church's conversion to an Augustinian priory began with a Kentish priest called Norman, who had studied under Anselm of Canterbury in France before returning to England and settling in Colchester.

Norman and a companion took this letter to the France, first to Chartres and then to Beauvais, where they learned the Rule of St. Augustine before returning to Colchester.

Pope Paschal II later confirmed the creation of St Botolph's Priory in a papal bull in August 1116.

The Priory was to be free from the jurisdiction of any person, secular or ecclesiastical, and on the death of Ainulf or any of his successors a new head was to be elected by the majority of the brethren and presented to the Bishop of London for consecration with special powers.

Pope Urban V on 1 July 1363 ordered the Archbishop of Canterbury to excommunicate the offending prior and canons if they could be found guilty.

This incident appears to have arisen out of disputes over control of the church of St. Peter and other matters in Colchester and over Layer de la Haye.

[6] In 1380 the prior and canons complained to the King Richard II that several people were pretending to be their attorneys and proctors, and were using forged letters to collect money from unsuspecting victims.

The king gave orders for the offenders to be arrested and sent to Newgate gaol, and the forged letters were to be delivered to the archbishop of Canterbury.

[6] On 20 February 1421 Pope Martin V granted a relaxation of penance to penitents who on the feast of St. Denis should visit and give alms for the conservation and repair of the priory, which was founded and sufficiently endowed for a prior and twelve canons, but had become impoverished.

[6] Early in 1534 the prior and seven canons, Robert Bawde, Richard Parker, William Shyrwyn, John Garrard, John Gyppys, Robert Rand and William Patche, took the oath of fealty under the Act of Succession, thus avoiding prosecution under the Treasons Act 1534.

On 26 May in that year it was granted with all its possessions, including the manors of Blindknights, Canwikes and Dilbridge to Sir Thomas Audley.

[2] The lady chapel contained an image of Mary, which had an Eternal Light burning in it funded by income from a piece of land at Colchester's Hythe port.

This thirteenth canon was to celebrate divine service daily at the altar of St. Thomas in the priory church for Master Simon's soul and the souls of his parents, Robert and Cecily; this agreement was confirmed by the Bishop of London and by the dean and chapter of St Paul's Cathedral.

Master Simon afterwards granted additional rents and tenements from which he assigned half a mark for the vesture of the thirteenth canon, 3s.

In case of failure to keep this agreement, the priory was to pay to the abbot or his successors a fine of £10, levied from its manors of Layer de la Haye, Peldon and Abberton.

An early source of income was from the tithes of the demesne of Hatfield, granted to the Priory by Henry I from his own personal estates.

[6] Henry also granted the canons of the priory a third share of the mill called Midelmeln (modern Middle Mill in Castle Park, Colchester), as well as confirming the grants made to them by Hugh FitzStephen, under a new condition that they should supply him during expeditions against Wales with a horse worth 5s., a sack and a pike.

Richard I granted a charter on 4 December 1189, in which he extended the list of liberties and confirmed their possessions in detail, these including the churches of Gamlingay in Cambridgeshire, Layer de la Haye and Marks Tey.

[6] St Botolph's Priory was led by a prior, whose seal was a pointed oval of yellow brown wax, 2½ in.