standard city plan. There are exceptions in detail, if not in overall form.

This remarkable civilization remained unified for nearly 700 years. Then, partly because of overexpansion of its trade networks, after about 1900 b.c. it gradually disintegrated into a regionalized pattern of cultures, referred to as late or post-Harappân. Within 150 years Mohenjo-Daro’s efficient urban government had deteriorated. Administrative breakdown was augmented by ecological factors. Recent research has established that most protohistoric cultures suffered three centuries of persistent drought from about 2200 b.c., perhaps activated by a sudden global climate change. The passing of the Indus-Saraswati cities can be attributed in part to changing river patterns, upsetting a river-based agricultural and trade economy that had already outgrown its strength. The Saraswati dried up, the Hakra-Nara’s tributaries were diverted eastward to the Jamuna River and westward to the Indus, and the course of the Indus itself began to change, resulting in frequent violent flooding of its southern reaches.

Further reading

Gupta, Swarajya Prakash. 1996. The Indus-Saraswati Civilization: Origins, Problems, and Issues. New Delhi: Pratibha Prakashan.

Possehl, Gregory L., ed. 1993. Harappan Civilization: A Recent Perspective. New Delhi: American Institute of Indian Studies.

Rao, Shikaripur Ranganatha. 1991. Dawn and Devolution of the Indus Civilization. New Delhi: Aditya Prakashan.

Mont-Saint-Michel

Normandy, France

Mont-Saint-Michel is a craggy, conical island, about half a mile (0.8 kilometer) across and standing half a mile from shore in the Gulf of Saint-Malo, near the border of Brittany and Normandy on France’s northern coast. The north side of the island is wooded and the west presents a barren face to the sea. A fortified village of fewer than 100 inhabitants huddles on the lower southern and eastern slopes and the great Benedictine abbey, dating from the thirteenth century, crowns the entire mount, towering about 240 feet (73 meters) above. The integration of monastery with village and both with the rock was noted by UNESCO as “an unequalled ensemble” when the site was inscribed on the World Heritage List in 1979. Mont-Saint-Michel is an architectural feat for that reason and others: the audacity displayed by the builders on so difficult a site and the harmony achieved between its parts, which were built in many architectural styles over five centuries.

The place known as Mont Tombe, which became Mont-Saint-Michel, has a spiritual history dating from pre-Christian times. There the Gauls had worshiped Belenus, the god of light, and there the Romans consecrated a shrine to Jupiter. By the fifth century a.d. the secluded crag and the Scissy Forest around it had become a retreat for hermits. There is a tradition that in 708 St. Michael appeared to Aubert, twelfth bishop of Avranches, directing him to build a sanctuary to the archangel on the mount. In October of the following year, Aubert consecrated a simple circular oratory, to accommodate about 100 people, and built cells to replace the earlier huts, but not before an abnormal tide—some sources say a tidal wave—had gouged a channel between rock and shore, creating the islet. At low tide a land bridge connects to the mainland across beaches of gray silt; at high tide it is covered by about 40 feet (14 meters) of water.

Under the sponsorship of Richard the Fearless, Duke of Normandy, Abbot Mainard occupied the island in 966 with twelve Benedictine monks from Monte Cassino. He built a rectangular chapel with 6.5-foot-thick (2-meter) stone walls on the ruins of the oratory. By that time, the Benedictines had enjoyed four centuries of prominence in western Europe and monasticism had reached a zenith. In France, the abbeys—there were about 120 of them— exercised great influence in many spheres: spiritual, artistic, intellectual, economic, and political. Besides the Benedictines, whose other Normandy houses were at Fecamp, Lessay, and Lonlay, the Premonstratensian (Canons had established themselves at Ardenne and La Lucerne. Eventually, Mont-Saint-Michel would become a magnet for thousands of the faithful from all over Europe.

The next building phase was initiated by Abbot Hildebert II in 1017. An extensive masonry foundation