is believed to be this site, and a socket to hold a cross (which is believed to have been erected later) is visible there. Manuscript and book production The production of Christian manuscripts, books and annals was an important activity in the Iona monastery. The Chronicle of Ireland incorporated annals compiled on Iona up to about 740. The Book of Kells, an illuminated manuscript, is believed to have been produced by the monks of Iona in the years leading up to 800. Stone crosses Stone crosses, both standing and lying, were used to mark graves in the Iona monastery. Large stone crosses were also erected, perhaps to broadcast key Christian messages, particularly in 800–1000. Their design reflected precious metal crosses. Some were carved from stone imported 50 miles by boat from Loch Sween. Other technology Remains of wood-turning and metal-working have been found at Iona, and of glass (windows and beads) that may date from the 7th century. Trade The Iona monastery's position in what was then a well-used seaway would have facilitated trade, as would St Columba's personal aristocratic background. Pigments from the south of France were used in Iona. Viking attacks, and subsequent movement between Abbeys The Iona Abbey was first attacked by Viking raiders in 795, with subsequent attacks taking place in 802, 806, and 825. During the 806 Viking attack, 68 monks were massacred in Martyrs' Bay, and this led to many of the Columban monks relocating to the new Columban Abbey of Kells in Ireland. The building at Kells took from 807 until the consecration of the church in 814. In 814, Cellach, Abbot of Iona, retired to Kells, but, contrary to what is sometimes claimed, it is clear from the Annals that Iona remained the main Columban house for several decades, despite the danger of Viking raids. In 825, St Blathmac and those monks who remained with him at Iona were martyred in a Viking raid, and the Abbey was burned. But only in 878 were the main relics, with Columba's reliquary shrine specified in the records, moved to Ireland, with Kells becoming the new main Columban house. Though not mentioned, this might well have been when the Book of Kells came to Kells. However, Iona Abbey was probably not deserted as its continued importance is shown by the death there in 980 of Amlaíb Cuarán, a retired King of Dublin. St Columba established