Glastonbury Abbey's documented history begins with late seventh-century royal land grants and archaeological evidence for an early Saxon church. Later monks promoted a much older Christian foundation associated with Joseph of Arimathea and a legendary Old Church, but those claims cannot be treated as verified first-century history. Under Abbot Dunstan in the tenth century, the monastery became an important center of Benedictine reform, royal patronage, learning, craft production, and burial. By the Norman Conquest it ranked among England's wealthiest religious houses.

Norman rule brought tension and rebuilding. In 1083 soldiers of Abbot Thurstin killed or wounded monks during a confrontation over new customs. Later abbots expanded the church and estates, but a devastating fire in 1184 destroyed the Old Church and much of the monastery. Henry II supported rebuilding, beginning with the richly carved Lady Chapel on the sacred earlier site. In 1191 the monks announced discovery of graves identified as King Arthur and Guinevere. The claim attracted patronage after the fire, though modern archaeology provides no basis for accepting the identification.

The rebuilt great church, cloister, abbot's complex, kitchen, chapels, and service buildings expressed enormous late medieval resources. Pilgrims came for saints, relics, and Arthurian associations. During Henry VIII's dissolution of the monasteries, Abbot Richard Whiting was convicted on a contrived treason charge and executed in 1539. Crown agents stripped valuables, roofs, lead, and furnishings, and later owners quarried stone for the town. Some structures, notably the Abbot's Kitchen, survived because they remained useful, while walls and foundations became ruins embedded in private grounds.

The Church of England acquired the estate through public subscription in the early twentieth century, opened it to visitors, and began conservation and excavation. Architect-archaeologist Frederick Bligh Bond mapped important remains but allowed spiritualist beliefs to influence his claims. Later excavations identified three Saxon church phases and refined the medieval plan. Standing arches, chapel walls, church piers, kitchen, and foundations contain original fabric, but wall tops have been capped, masonry reset, paths laid, and fragile areas stabilized. Digital reconstructions and marked outlines are interpretive tools, not rebuilt medieval buildings.

A registered charity now preserves the ruins, museum collections, Abbey House, and landscaped grounds, relying heavily on admissions and donations. Access, worship events, excavations, and conservation zones vary. Interpretation should hold documentary history, archaeology, belief, and legend in productive tension rather than presenting Joseph or Arthur as proven facts. Glastonbury's authenticity lies in its Saxon and medieval deposits, roofless standing masonry, dissolution damage, and century of research and repair. The site is a conserved ruin and living place of memory, not a complete monastery restored to an imagined golden age.