Powerful chiefdoms are emerging along the middle Nile valley.
One of the main roles of these chiefdoms is to control the flood waters of the Nile, so as to irrigate the lands along the river banks effectively. Only thus can the fields be made fertile and the growing population of the Nile valley fed.
This requires the proper co-ordination of the work of thousands of people, in building canals and dykes and digging irrigation channels. The chiefs therefore exercise a high degree of control over the lives of their subjects. They are aided by a hierarchy of officials and overseers, groups of people who are developing the skills – in record keeping, mathematics, engineering and management – which will over the coming centuries bring to fruition the magnificent achievements of one of the great civilizations of world history, Ancient Egypt.1)http://www.timemaps.com/civilization/Ancient+Egypt
ORIGINAL SOURCE: timemaps.com