The arrival of the cult of St Michael is recounted in a 10th Century manuscript called “La Revelatio ecclesiae sancti Michaelis”. According to this foundation text, one night in 708, Aubert, the Bishop of Avranches, saw the Archangel Michael in a dream commanding him to build a church on the rock.

When the Bishop expressed doubts, the angel pierced a hole in his skull with his finger!  So Aubert had a chapel built on this site. In the troubled context of the Merovingian era, the fervour for the Archangel amongst the faithful spread quickly and this spot became a place of pilgrimage which was soon renamed Mont Saint Michel.

The pre-Romanesque Church was built before the year 1,000.  In the 11th Century the Romanesque Abbey Church was founded over a set of crypts where the rock comes to an apex, and the first monastery buildings were built up against its north wall.  In the 12th Century the Romanesque Monastery buildings were extended to the west and south. In the13th Century a donation by the King of France, Philip Augustus, in the wake of his conquest of Normandy enabled a start to be made on the Gothic section of the "Merveille", two three-storey buildings, crowned by the cloister and the refectory.

In the 14th Century the Hundred Years War made it necessary to protect the Abbey behind a set of military constructions

 enabling it to hold out against a siege lasting 30 years.  In the 15th Century the Gothic flamboyant Chancel replaced the Romanesque Chancel of the Abbey church.  Finally work continued up until the 18th Century to build the Abbey living quarters which makes up the south front of the Abbey.

In 1793, revolutionaries transformed the abbey into a prison and 1828 saw the Garrison built. An imperial decree of 1863 finally put an end to this sacrilege

After being used as a prison during the Revolution and the Second Empire the Abbey was turned over to the Historic Monuments Department in 1874, since when it has become open to the public all year round.  Since 1969 a monastic community has provided a permanent spiritual presence as well.

Exciting times - Work today: Circa 1879 road access was built and gradually silt and sand are filling the Bay and natural grasses have began to take over.

An access bridge is to be constructed allowing a shuttle to transport 2,900 people in 8 minutes, the car parks will be 2 km inland, cycle, bridle and footpaths will be constructed to allow easier access and help preserve the flora and fauna.

In March 1995, the State, Basse-Normandie areas, Brittany as well as the departments of the Manche and Ille-et-Vilaine joined to restore with the mount its maritime character. After 4 years of studies, the project is visual today. Simulations on a giant model of the bay where the hydro-sedimentary phenomena were observed, confirm the need for replacing the dam-road by a bridge leaving free course to the currents. But these simulations also showed that the destruction of the dam is not sufficient, if one wants to preserve the insularity of the Mount-Saint-Michel in time.  The River Couesnon, that splits Normandy from Brittany at the bridge Pontorson, will be widened from 30 metres to 80 metres,  divided into 2 channels and again become tidal, this will assist the natural movement of the silt and sand. A reservoir of 900,000 m3 will be built up stream as a flood barrier to the land.