The island is steeped in local folklore and history. Children listen intently to tales of "Jack the Giant killer" as they walk past the well were the Giant was eventually trapped. Cornish Legend holds that the Mount was built by the giant, 'Cormoran'. Cormoran, would wade ashore from the island, to snatch cows and sheep as they grazed in the local fields around Marazion. A local boy rowed out to the island whilst Cormoran slept. He worked through the night; digging a deep pit half way up the northern slope of the Mount. By morning, the pit was complete; Jack stood to one side of it and blew on his horn to wake the mighty Cormoran. The giant ran down the hillside, with the glare of the early morning sun dazzling his eyes. He failed to see either Jack or the pit and fell headlong into it. The grateful locals gave Jack the title 'Jack the Giant Killer' and a local rhyme was created about his exploits.
Here's the valiant Cornishman
Who slew the Giant Cormoran.
As you walk up the main pathway from the harbour to the Castle, you pass the
heavily shuttered well, where the giant fell.
Or whether thou to our moist vows deny'd,
Sleep'st by the fable of Bellerus old,
Where the great vision of the guarded Mount
Looks toward Namancos and Bayona's hold;
Look homeward Angel now, and melt with ruth.
And, O ye Dolphins, waft the haples youth.
In the great Celtic tragedy of Tristan and Isolde, which may be partly historical, the hermit Ogrin was sent by King Mark, to St. Michaels Mount to buy clothes of fine wool and linen, for Queen Isolde. During the 12th century, the legend was firmly based around the Cornish Coastline, Castle Dore near Fowey, the Forest of Moresk near Truro and St. Michaels Mount, but, in the political upheaval of mediaeval Britain, story was linked to the Legend of King Arthur and the Castle at Tintagel.
The mount itself, is dedicated to St. Michael, whom in Cornish Legend; appeared to a group of Cornish fishermen in 495 AD - standing high on a rocky ledge on the western side of the Mount. This is The Great Vision of the Guarded Mount from Milton's Lycidas (A lament for a friend drowned during a passage from Chester on the Irish Seas, 1637).
The island/peninsula was most certainly a trading place for tin since ancient times. It is a viable candidate for the famous trading island called Itkin by the Phoenicians who traded tin with the native Britons before the common era. The island could have held the valuable tin offshore allowing the strangers to trade without actually setting foot on the mainland.
According to the folk tale, Jack the Giant Killer slew the Cornish Giant Cormoran after tricking him to fall into a pit on this island. The greenstone on the island is supposed to have been brought there by the Giantess Cormelian, wife of the Giant Cormoran, in her apron. Cormoran, building the mount of granite, saw that she had brought the wrong rock, and killed her. Cormelian dropped the stones as she fell dead and is said to be buried under the pile of greenstone still found today.
A sister location, Mont St Michel is located across the English Channel along the northern coast of Normandy.