The name Glastonbury is associated with the Arthurian tradition in several ways. Most famously, Glastonbury is said to have been Avalon, the “apple isle,” where King Arthur was taken after his final battle. Avalon was said to have been a healing place, where Arthur could recover and await the time when he would be needed again.
It was after the terrible battle of Camlann, when tradition that Arthur was mortally wounded. (Or was he?) The story goes that a healing priestess (in some stories Morgan LeFay herself) led a group of other healing priestesses from the sacred isle of Avalon to the battlefield, where they spirited Arthur away to the healing isle itself.
The story goes that Glastonbury was indeed this Avalon; and indeed, at the time that Arthur was thought to have lived, Glastonbury was an island. Whether it was Avalon has not been decidedly determined. The story does not, however, say whether Arthur was healed and made ready for his promised return. Rather, the story tells us only that Arthur was taken to the healing isle.
History doesn’t have a lot to say about these particular elements of the Arthurian tradition. History, however, can tell us when Glastonbury Abbey was built. That would be 704, at the direction of King Ine of Wessex, who put up a good bit of his own money to have a Christian church and abbey built at Glastonbury, to be populated by Benedictine monks.
On the site already was the Wattle church, a truly ancient building that had survived the invasion intact. At this very church in 704, King Ine signed the Charter of Ine, granting to the church royal protection and confirming for it the mission to spread the word of the Christian God.
So then we have the agreement to build the abbey signed in 704. When was Arthur thought to have lived? Well before this date, no matter whose dates you accept. So he could not have been a frequenter of Glastonbury Abbey. He could very well have visited the Wattle Church, however.
Glastonbury Abbey had its meager beginnings in the signing of a document by a powerful king in the early 8th Century. It would live to see many great days in the years ahead before being pillaged and left for dead.
In years to come, monks there would claim that they had found the actual body of Arthur himself, authors would write Glastonbury into the Arthurian story, and the little abbey that could would find itself the center of a great deal of attention.