Built on the summit of a rock, the impregnable steepness of which provided a natural rampart north and west, it depended solely upon the advantages of its position for defence. Its situation in the midst of a treacherous sandy plain--a position which gave rise to the mediæval name, _Le Mont St. Michel au Péril de la Mer_--secured it against attempts at investiture, and even to a great extent against sudden assaults. Enclosures of stone or wooden fences surrounded it at those points on the east where the less rugged nature of the surface rendered access comparatively easy, and where stood the entrance, with the various habitations which had grouped themselves round it. The so-called _town_ had been founded in the tenth century by a few families decimated by the Normans, in their raids upon Avranches and its neighbourhood after the death of Charlemagne. In the thirteenth century it consisted of a small number of houses which, by way of security against the vagaries of the sea, were built upon the highest point of the rock to the east. In 1203 the greater part of the abbey, the church excepted, was destroyed during the wars between Philip Augustus, King of France, and John, King of England. Historic records prove conclusively that the abbey had no defensive works properly so-called in the twelfth and early part of the thirteenth century. From this period onwards abbeys, more especially those of the Benedictine orders, were transformed into regular fortresses capable of sustaining a siege. The abbots, in their character of feudal lords, fortified their monasteries to ensure them against disasters such as had marked the early years of the thirteenth century. Mont St. Michel is one of the most curious examples of such fortification. The original architects of the abbey seem to have been unwilling to diminish the height of the mount by levelling. Resolving to detract in no degree from the majesty of so splendid a base for their church, they set about their work on the same principle as the pyramid builders. Our illustrations show how the buildings were raised partly on plateaux circumscribing the apex of the mount, partly on that apex itself. The result is that the monastery, as we see it, has a core of rock rising at its highest point to the very floor of the church. The ring of lower stories rests upon walls of great thickness, and upon piers united by vaults, the whole forming a substructure of perfect solidity. The section made through the transept (Fig. 153) gives an exact idea of the portion which dates from the eleventh and twelfth centuries, and of the buildings which gradually grouped themselves round this nucleus, such as the so-called _Merveille_ (Marvel) to the north, and the abbot's lodging to the south. [Illustration: 153. ABBEY OF MONT ST. MICHEL. TRANSVERSE SECTION, FROM NORTH TO SOUTH[55]] [55] _Description de l'Abbaye du Mont St. Michel et de ses Abords_, by Ed. Corroyer; Paris, 1877.