Iona Abbey occupies a small Hebridean island whose religious influence reached far beyond its shores. In 563 the Irish monk Columba arrived with twelve companions and founded a monastery within the Gaelic kingdom of Dál Riata. The community became a center of worship, learning, manuscript production, and missionary activity. Monks trained on Iona helped carry Christianity among the Picts and into northern Britain; Aidan, who later founded Lindisfarne, belonged to this tradition. Columba's death in 597 strengthened the island's role as a place of pilgrimage, and his successors developed a network of Columban monasteries across Ireland and Britain.

Iona's artists produced carved high crosses and richly illuminated manuscripts. The Book of Kells is often connected with the community, whether begun on Iona or created within its wider monastic network. Wealth and reputation also made the island a target. Viking raiders attacked in 795, 802, and 806; the 806 assault killed sixty-eight members of the community. In 825 Abbot Blathmac and other monks were killed after refusing to reveal the location of sacred treasures. Relics and manuscripts were gradually moved between Iona, Kells, and other houses, yet monastic life on the island continued despite repeated violence.

Political control shifted during the Norse age. In the twelfth century Somerled and his descendants restored Gaelic lordship in the region. Around 1203 his son Ranald invited Benedictine monks to establish a new abbey on the Columban sacred ground, while an Augustinian nunnery was founded nearby. The reorganization provoked resistance from Irish Columban clergy, and a raiding force associated with two Irish bishops attacked in 1204. The new stone monastery nevertheless endured. Under the Lords of the Isles, especially the Macdonald dynasty, Iona became an ecclesiastical and burial center for western Scottish elites. Medieval grave slabs and monuments record that patronage.

The Scottish Reformation brought another rupture. Monastic institutions were suppressed in the sixteenth century, buildings were stripped, and the abbey entered a long period of decay. Pilgrims and antiquarians continued to visit, preserving Iona's reputation even as roofs collapsed and sculpture weathered. In 1899 the Duke of Argyll transferred the ruins to the Iona Cathedral Trust, which began restoring the church. The work reflected contemporary hopes that the island might again become a center of Christian unity and renewal.

In 1938 minister George MacLeod founded the Iona Community. Clergy, craftsmen, and unemployed workers rebuilt parts of the monastic complex while creating an ecumenical movement committed to common life, peace, and social justice. Restoration continued through the twentieth century, and care of the monuments later passed to the state. The abbey remains an active place of worship and pilgrimage. Its surviving fabric embodies repeated cycles of creation, attack, dispersal, reform, ruin, and renewal, linking early medieval Christianity, Viking conflict, the Lordship of the Isles, the Reformation, and modern ecumenism in one continuously meaningful landscape. Modern pilgrimage revived strongly in the twentieth century, especially through the ecumenical Iona Community founded by George MacLeod in 1938. Its members helped reconstruct communal buildings and restored the abbey as a place of worship, work, and international encounter, adding a new reforming chapter to Iona's long religious history.