Hilbre Island may already have been a hermitage before the Norman invasion or at least a place of pilgrimage based around the lore of St Hildeburgh. In about 1080 a cell and church for Benedictine monks was established on Hilbre Island as a dependency of Chester Cathedral. Although not named directly, it is believed that all three islands were mentioned in the "Domesday Book" in which mention is made of "Chircheb" (West Kirby) having two churches: one in the town and one on an island in the sea.