In the 1920s a 4,500 year old civilization was discovered on the Indian subcontinent. Named the Indus Valley Civilization for its development on the floodplains of the Indus River Valley in c. 2500 BCE, it quickly flourished and spread over a large area. Its reach extended over modern-day Pakistan and northwest India. This civilization is of special interest for its sophisticated urbanization which rivalled that of contemporaneous Ancient Egypt. Its peak population may have exceeded five million people.
Two of the largest cities of the Indus Valley Civilization were Harappa, a major center of the upper Indus Valley, and Mohenjodaro, a major center of the lower Indus Valley. Early archaeological findings at these cities consisted of weights, measures, pottery, and decorated seals. The seals and shards of pottery contain symbols of the yet undeciphered Indus Valley Script. One such pottery shard dates back to 3500 BCE, providing evidence for writing that predates Egyptian hieroglyphs, making it the earliest written script discovered so far.
Excavations have shown that Harappa was inhabited as far back as 3300 BCE. The beginnings and culture of the Indus Valley Civilization go even further back, to at least 6000 BCE. From these roots emerged city-states with similar writing systems, standardized weights, pottery styles, and building methods. Beads, pottery, lumber, and other materials were traded in the region. These shared elements have been found by archaeologists all the way from Afghanistan to Mumbai.
The sophisticated urban planning of cities in the Indus Valley Civilization surpasses that of many places in the modern world. Built on platforms, the cities were protected from seasonal floods. Paved roads were flanked by covered drains. These drains were a part of the advanced drainage systems that provided inhabitants with the world’s earliest flush toilets. All homes were two stories and built with standardized mud bricks. Such uniformity in building and planning suggests a strong central government.
Very little is known about the possible religion of the Indus Valley. The dead were buried with food alongside them in simple wooden coffins. Terracotta images of people and animals have been found, as well as many female figurines. Some seals and tablets depict figures seated in meditation-like postures. Also important are discoveries of smooth linga and yoni stones, identical to the type which are found in modern Hinduism.
The Indus Valley Civilization relied heavily on two rivers, the Ghaggar-Hakra River (thought by some scholars to be the Vedic Sarasvati River), and the Indus River. The Ghaggar-Hakra eventually dried up and the Indus changed its course. These events likely led to the decline of the Indus Valley Civilization. Many settlements were abandoned due to the lack of access to a river.
Though the Indus Valley Civilization eventually disappeared, its practices, beliefs, and materials spread to later cultures. In this way, it likely contributed to the subsequent religious and cultural history of India.