The logistics of island burial were a practical reality for many Irish communities well into the early modern period, with coffins ferried across water to sites considered sacred or simply traditional, and Church Island appears to have been one such place.

The record of this comes from James McParlan, who in 1802 documented the island and noted that the graveyard had, in former ages, served as the burial place for the parish of Calry. Calry is a parish on the outskirts of Sligo town, and the fact that its dead were once carried to an island for interment suggests the site had considerable ecclesiastical significance in earlier centuries. The graveyard is associated with a church on the same island, and this pairing of church and burial ground on an isolated patch of land is a pattern found across Ireland, where early Christian communities often favoured island locations for monastic or devotional purposes, both for the symbolic separation they offered and for practical reasons of defence and retreat. By the time McParlan was writing, the island's role as a parish burial ground had clearly passed into memory rather than current use, already referred to in the past tense as something belonging to former ages.