The name Corrib is a corruption of Lough Oiribsean or Oiribsiu, the name being a local name for a widely worshipped pagan deity, Mannanan Mac Lir. Lir was a sea god and his son Mannanan, whose name is linked to the name Man in Isle of Man, was said to ride a chariot pulled by magical steeds across the waves. But there is very little genuine history from the area until the Middle Ages. Marine archaeologists have uncovered remains of dug-out canoes, so it seems that there was boat commerce on the lough, and as mesolithic and neolithic flint artefacts have been found in the region, it is likely that boat commerce was part of the life of the lough from an early time. A boat from the Viking age carrying three axe heads was found, but whether or not it was a Viking boat is not clear. The remains of a Victorian pleasure yacht were also located. Ireland is protective of its archaeological heritage and so special government permission to dive to the wreck sites is required.
So far no one has located any Crannogs on the lough. These are pile dwellings constructed on artificial islands, or on islands selected and enhanced for the purpose. The ancient and mediaeval Irish were expert crannog builders, so I would not be surprised were crannog remains to be discovered.
But the mediaeval period saw some conventional structures erected on larger islands. There are remains of a mediaeval monastic building in Inish na Goile, and from the nineteenth century some peasant cottage remains are still present. Inish means island. Another name for an island is illaun, and one island on the lough is known as Ardillaun, high island.
The lough was in the territories of the Anglo-Norman Burkes [De Burgos, Bourkes] who had been awarded land in Connemara and who in 1333 finally abandoned their Anglo-Norman identity and declared themselves Irish. The Burkes were in long-term conflict with the "Ferocious" O'Flaherties and their faithful allies, the Anglo-Norman Joyces. One story is told of magical interference or assistance, depending on whether you support the Burkes or the O'Flaherties. An O'Flaherty chief had left his wife and family for safe keeping on one of the islands while he attacked the Burkes, but was defeated. The result was that his family were stranded on the islet. Enter the Sidhe, the fairies, who looked kindly on the O'Flaherties because they had respected fairy territory. The magical fair folk brought provisions to the stranded O'Flaherties until they were rescued. Make of this what you will.
The island known as Castle Kirk Island [Caislean na Circe] is near the Lough's northern shore and contains the remains of a tower house dating back t0 1118, which makes it pre-Norman. A Caislean [pronounced castleen] is a small castle. It is considered an important archaeological site because, despite its now ruined state [Thanks Cromwell!] it is one of the oldest stone buildings in Ireland. It at one time housed and protected Grainne O'Malley, the pirate queen of the O'Malley Clan, who was married to an O'Flaherty chief. She is sometimes miscalled Grace O'Malley.
Also at the North end, in the Mayo part of Corrib, is Ashford Castle, an elegant nineteenth century country house and lodge once voted the world's best hotel. It stands on Leaf Island and is connected to the shore by a short bridge. The picture below shows the person who provided the photographs for this article at Ashford Castle with her husband.