A highly developed urban civilization in the lower valley of the River Indus, in South Asia, which flourished from about 2500 to 1500 bc. Archaeological excavation, which began in the 1920s, is still being carried out and many important questions remain unanswered. City life seems to have ended abruptly c.1500 bc, possible causes being flooding, alteration of the course of the Indus, overpopulation, or an Aryan invasion.
Among more than 70 sites now excavated, those at Mohenjo-Daro, Harappa, Kalibangan, and Lothal seem particularly important for revealing a civilization based on the use of bronze, copper, and stone tools, and also city planning, including granaries, baths, drains, and straight streets. There is evidence of contact with Mesopotamia, but the script, known by the discovery of seals which were probably used in trade, has not yet been deciphered. The nature of religious worship is also uncertain, although stone and terracotta figures, as well as motifs on the seals, suggest links between the Indus cults and later post-Aryan Hindu religious concepts. The civilization provides evidence of an important stage in India's past, and of one of the world's first highly developed urban communities.
Indus-civilization.Like other early civilizations in Egypt and Mesopotamia, the Indus civilization flourished in a region that despite low rainfall was irrigated by a great river. The civilization covered a very wide area and the discovery of new sites is constantly extending the known range of its cultural influence. The citadels of Mohenjo-daro and Harappa were both built on artificial mounds on riverside sites. Major buildings were substantial and the system of sanitation and drainage with extensive brick culverts, one of the hallmarks of the Indus civilization, implies careful planning under close state control.