The Indus Valley Civilization was one of the three earliest civilizations in the Old World, located along the Indus River valley in modern-day Pakistan and northwest India from 3300-1300 BCE. At its height, the civilization's cities like Harappa and Mohenjo-Daro had over 5 million inhabitants and sophisticated urban planning with drainage and water supply systems. While its writing still remains undeciphered, the Indus Valley Civilization developed new crafts and technologies. The civilization began declining around 1800 BCE due to changing river patterns and flooding, and was later influenced by migrations of Aryan peoples into the region starting around 1500 BCE.

1. THE INDUS VALLEY
CIVILIZATION

2. THE INDUS VALLEY CIVILIZATION
The Indus Valley Civilization was a Bronze Age civilisation (3300–1300
BCE; mature period 2600–1900 BCE, pre-Harappan cultures starting
c.7500 BCE) in northwest Indian subcontinent (including present day
Pakistan, northwest India) and also in some regions in northeast
Afghanistan.

4. RIVER INDUS AND SARASVATI
Along with Ancient Egypt and Mesopotamia, it was one of three early
civilisations of the Old World, and the most widespread among them,
covering an area of 1.25 million sq km. It flourished in the basins of the
Indus River, one of the major rivers of Asia, and the now dried up
Sarasvati River.

5. URBAN PLANNING
At its peak, the Indus Civilization may have had a population of more
than 5 million. Inhabitants of the ancient Indus river valley developed
new techniques in handicraft and metallurgy (copper, bronze, lead, and
tin). The Indus cities are noted for their urban planning, baked brick
houses, elaborate drainage systems, and water supply systems.

6. HARAPPA AND MOHENJO-DARO
The Indus Valley Civilization is also known as the Harappan Civilization,
after Harappa, the first of its sites to be excavated in the 1920s, in what
was then the Punjab province of British India, and is now in Pakistan.
The discovery of Harappa, and soon afterwards, Mohenjo-Daro, was
the culmination of work beginning in 1861 with the founding of the
Archaeological Survey of India in the British Raj.

8. THE CITY LIFE
The evidence suggests they had a highly developed city life; many
houses had wells and bathrooms as well as an elaborate underground
drainage system. The social conditions of the citizens were comparable
to those in Sumeria and superior to the contemporary Babylonians and
Egyptians. These cities display a well-planned urbanization system.

9. WRITING
The Indus Civilization had a writing system which today still remains a
mystery: all attempts to decipher it have failed. This is one of the
reasons why the Indus Valley Civilization is one of the least known of
the important early civilizations of antiquity. Examples of this writing
system have been found in pottery, amulets, carved stamp seals, and
even in weights and copper tablets.

11. RELATIONSHIP BETWEEN CITIES
Another point of debate is the nature of the relationship between
these cities. Whether they were independent city-states or part of a
larger kingdom is not entirely clear. Because the writing of the Indus
people remains undeciphered and neither sculptures of rulers nor
depictions of battles and military campaigns have been found, evidence
pointing in either direction is not conclusive.

12. BEGINNING OF THE DECLINE
By 1800 BCE, the Indus Valley Civilization saw the beginning of their
decline: Writing started to disappear, standardized weights and
measures used for trade and taxation purposes fell out of use, the
connection with the Near East was interrupted, and some cities were
gradually abandoned.

13. THE DECLINE
The reasons for this decline are not entirely clear, but it is believed that
the drying up of the Saraswati River, a process which had begun
around 1900 BCE, was the main cause. Other experts speak of a great
flood in the area. Either event would have had catastrophic effects on
agricultural activity, making the economy no longer sustainable and
breaking the civic order of the cities.

14. THE ARYANS
Around 1500 BCE, a large group of nomadic cattle-herders, the Aryans,
migrated into the region from central Asia. The Aryans crossed the
Hindu Kush mountains and came in contact with the Indus Valley
Civilization. This was a large migration and used to be seen as an
invasion, which was thought to be the reason for the collapse of the
Indus Valley Civilization, but this hypothesis is not unanimously
accepted today.

15. THE AGRICULTURE
Thus, the Indus Valley Civilization came to an end. Over the course of
several centuries, the Aryans gradually settled down and took up
agriculture. The language brought by the Aryans gained supremacy
over the local languages: the origin of the most widely spoken
languages today in south Asia goes back to the Aryans, who introduced
the Indo-European languages into the Indian subcontinent.

16. THE SURVIVORS
Other features of modern Indian society, such as religious practices
and caste division, can also be traced back to the times of the Aryan
migrations. Many pre-Aryan customs still survive in India today.