Inishmurray may be named after the early saint, Muiredach mac Echdach (fl. early 6th century) of Killala. There are remains of an early Irish monastic settlement. Laisrén (Saint Molaise) Mac Decláin reputedly founded a monastery here in the 6th century. He was confessor of Saint Columba (Colmcille) after the Battle of Cúl Dreimhne on the mainland nearby.
The island's ecclesiastical settlement was attacked in 795 and again in 807 by the Vikings, and eventually the monks abandoned the island and it remained uninhabited until the first secular settlement, probably in the 12th century.
The enclosure wall is impressive - reaching 4.5 metres in height at its highest point and up to 3 metres thick. The site contains various ecclesiastical buildings including enclosures, a stone-roofed oratory, two churches, a clochán, a large beehive-shaped cell, a holy well and other remains including cross slabs suggesting foreign influences. The whole complex is composed of what is probably local sandstone rubble.
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The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.