During the Bronze Age, an urban revolution also took place. Sumer and Akkad were two great urban civilization of this age. Towns become centres of a number of activities.

Here temples were constructed with the labour of hundreds of workers who had to be supervised and directed. To do this, an architectural plan had to be drawn in advance.

These outlines were laid out with the aid of strings. In India, the ancient knowledge of architecture was called the Sulve (string) Sutra. The impressive temples thus constructed also needed to be administered.

As worship was so highly institutionalised, here it was natural that a specialized class of priests should also emerge. These priests were the first carriers of the literary tradition and predictably, literary records generally portray the perspective of the priestly class.

The solar calendar was developed in the Nile Valley. Mohenjodaro and Harappa which were urban civilizations of a later Bronze Age, also shared the characteristics of this revolution and knowledge with other Bronze Age civilisations.