In 1856, a group of British railroad engineers uncovered an ancient and advanced civilization. The engineers were laying tracks through the Indus River Valley in present day Pakistan. They searched the area for stone to make ballast. Ballast is crushed rock placed around railroad tracks to drain water from the path of the train. The engineers found bricks that seemed very old, but were formed exactly alike. The local people told the engineers of the ruins of an ancient city made of the same bricks. The engineers soon realized that the bricks were part of one of the earliest advanced civilizations in history.
Archaeologists later discovered more than 1000 settlements along the banks of the Indus River. We don’t know what those ancient people called the cities they lived in, but we now refer to the two largest as Harappa, after a nearby village, and Mohenjo Daro, a local term that means “hill of the dead.”
Harappa and Mohenjo Daro were expertly planned cities that flourished more than 4500 years ago. The cities were built with a grid pattern of wide, straight streets. Thick walls surrounded the cities. Many people lived in sturdy brick houses that had as many as three floors. Some houses had bathrooms and toilets that connected to the world’s first sewers. A system of canals provided a reliable source of water for growing wheat and barley. There is also evidence that people herded sheep, cattle and goats.
The ancient people of the Indus River Valley had a highly advanced knowledge of mathematics and a sophisticated system of weights and measures. For example, the bricks they built with–even those used in different cities–were the same size. This suggests that the cities may have had the same government. Clay tablets indicate that the people of the Indus River Valley developed a writing system that may be even older than Sumerian writing.
Archaeologists have also found evidence of musical instruments, toys and games, and pottery. The people of the Indus River Valley were very interested in cleanliness. Excavators have uncovered evidence of combs, soaps, and medicine. Archaeologists found a gravesite with the remains of people whose teeth had been drilled, so the cities may have practiced a primitive form of dentistry.
The Indus River Valley cities traded with places as far away as Mesopotamia. The people made jewelry from stones. Traders also sold cotton cloth and hard wood from the teak trees that grew in the valley.
The a ncient cities along the Indus River Valley may have been home to more than five million people, but the civilization went into decline about 1700BCE.
What happened to the Indus River Valley cities remains a mystery, and the clues left behind provide many possible explanations.
The people of the Indus Valley cities may have unintentionally destroyed their environment. They may have overgrazed their land or exhausted their soil. There is evidence that the Indus Valley people cut down the forests in their region. In addition to leaving the people without wood for building or fuel, the lack of forest cover could have caused severe flooding.
It is also possible the same moving tectonic plates that created the Himalayas may have caused a devastating earthquake, or the people may have been defeated by another culture.
What we know about the Indus civilization is still evolving. Archaeologists have excavated only a fraction of the many cities and settlements of the region. We have not yet deciphered their writing, but if we do, we may learn their form of government, their religious beliefs, and the social structure of their society. In time, we may understand why the civilization developed, how they thrived for more than a millennium, and what became of the ancient people of the Indus River Valley.