One of the oldest civilizations of the world evolved in and around what is known as Punjab (Pakistan), around 6000 BC. The first traces of civilization originated in Mehrgarh (6000 BC).
Later two, more dominant, cities followed Mohenjo daro (mound of dead) and Harappa around. These cities cultured along the Indus River Valley in Sindh, Punjab, Uttar Pradesh, Gujarat, Baluchistan, Sind and the Makran coast.
Harappa and Mohenjo daro were two most planned cities in ancient world. The roads were had a sophisticated covered drainage system, road were made at right angles few highly distinct monuments. Great Bath of Mohenjo daro (now in Pakistan) was one of the most phenomenal monument. The cities used baked bricks for their construction, this is what is done even today!
There was a distinction between the upper and lower class in the society.
Merchants of Harappa and Mohenjo daro mainly traded on the banks of Indus river. Discovery of bronze had taken place and there were artist and craftsmen who made toys, ornaments, utilities,statues for trade.
Ladies in that society were quite a bit into fashion, just like today. Merchants used owned seals (rectangular in shape) as a trade copyright. Harappans traded with Sumerians in far Persia.
Around 1900 BC to 1200 BC both Harappa and Mohenjo daro declined. It was sad that such cultured civilization have to come to an end.
Some predict the cause of decline were the constant flooding of Indus river every year, probably a huge flood or two engulfed both the town.
Although, some others believe that the civilizations could not save themselves from barbaric attacks from the Aryans who later captured the areas.