The abbey controlled large tracts of the surrounding land and was instrumental in major drainage projects on the Somerset Levels.
This legend is intimately tied to Robert de Boron's version of the Holy Grail story and Glastonbury's connection with King Arthur from the early-12th century.
[7] William of Malmesbury reports the terms of a grant of land made by King Gwrgan of Damnonia to the "old church" at Glastonbury in AD 601 in the time of Abbot Worgret.
Saxons under Cenwalh of Wessex conquered Somerset as far west as the River Parrett, perhaps with the intention of gaining control of the abbey.
Cenwalh allowed the British abbot, Bregored, to remain in power, a move perhaps intended as a show of good faith to the defeated Britons.
[9] King Ine of Wessex enriched the endowment of the community of monks established at Glastonbury[10] and reputed to have directed that a stone church be built in 712,[11] the foundations of which form the west end of the nave.
[16] The medieval Glastonbury Canal was built about the middle of the 10th century to link the abbey with the River Brue, a distance of about 1.75 kilometres (1,900 yd).
His work "On the Antiquity of the Glastonese Church"[25] was compiled sometime between 1129 and 1139 as part of a campaign to establish the abbey's primacy against Westminster.
[26] These problems and the discrepancies between "On the Antiquity" and his own later histories has led many scholars to assume that William's original text was more careful and its accounts of "Phagan" and "Deruvian", along with various passages about Arthur, were later additions meant to bolster the monks' case.
[26][28][29] Early drainage work on the Somerset Levels was carried out in the later years of the 12th century, with the responsibility for maintaining all the watercourses between Glastonbury and the sea being placed on named individuals among whom were Ralph de Sancta Barbara of Brentmarsh.
[16] The importance of this industry is illustrated by a series of acrimonious disputes between Glastonbury and the Dean and Chapter of Wells Cathedral.
Above it, under the covering stone, according to Giraldus, was a lead cross with the unmistakably specific inscription Hic jacet sepultus inclitus rex Arturius in insula Avalonia ("Here lies interred the famous King Arthur on the Isle of Avalon").
[40] According to Giraldus, the digging for the tomb was prompted by the intelligence obtained by Henry II from an "aged British (Welsh) bard" (Latin: historico cantore Britone audierat antiquo).
William of Malmesbury does not refer to Arthur's tomb but elaborates on the pyramids of varying height, upon which were statues with inscriptions "Her Sexi, and Bliserh ... Pencrest, Bantomp, Pinepegn, etc.
"[44] Historians today generally dismiss the authenticity of the find, attributing it to a publicity stunt performed to raise funds to repair the Abbey, which was mostly burned in 1184.
The fact that the search for Arthur's body is connected to Henry II and Edward I, both kings who fought major Welsh wars, has had scholars suggest that propaganda may have played a part as well.
Savaric secured the support of Pope Celestine III for the takeover the abbey as the seat of his bishopric, replacing Bath.
In his support, Savaric obtained letters from various ecclesiastics, including the Archbishop of Canterbury, Hubert Walter, that claimed that this arrangement would settle longstanding disputes between the abbey and the bishops.
With the succession of John as king in place of his brother Richard in 1199, Savaric managed to force his way into the monastery and set up his episcopal see within the abbey.
Tithe barns were built to hold the crops due to the abbey including those at Doulting,[54] Mells[55][56] and Pilton.
The abbey was stripped of its valuables[60] and Abbot Richard Whiting (Whyting), who had been a signatory to the Act of Supremacy that made Henry VIII the head of the church, resisted and was hanged, drawn and quartered as a traitor on Glastonbury Tor on 15 November 1539.
[61] After the Dissolution, two of the abbey's manors in Wiltshire were sold by the Crown to John Thynne and thereafter descended in his family, who much later became Marquesses of Bath.
When Seymour was attainted in 1551, the abbey site reverted to the crown, but the weavers remained until they were removed in the reign of Queen Mary.
In 1559 Elizabeth I of England granted the site to Peter Carew, and it remained in private ownership until the beginning of the 20th century.
[64] He was dismissed by Bishop Armitage Robinson in 1921, because of his use of seances and psychic archaeology[65][66][67] but is remembered as the man who "galvanised our cultural understanding of Glastonbury".
[68] Pilgrimages continue today to be held; in the second half of June for the Anglicans and early in July for the Catholics and they attract visitors from all over Western Europe.
[71] The 14th century abbey barn is also open to the public, outside the walls, as part of the Somerset Rural Life Museum.
There is also surviving stonework from the south nave aisle wall, west front and the Galilee along with its crypt linked to St Mary's Chapel.
[76] The 14th century octagonal building is supported by curved buttresses on each side leading up to a cornice with grotesque gargoyles.
[85] William of Malmesbury suggested that relics relating to others, including the following, were deposited at Glastonbury: A specimen of common hawthorn found at Glastonbury, first mentioned in an early 16th-century anonymous metrical Lyfe of Joseph of Arimathea, was unusual in that it flowered twice in a year, once as normal on "old wood" in spring, and once on "new wood" (the current season's matured new growth) in the winter.