The civilization of ancient Egypt was based on a finely balanced control of natural and human resources, characterised primarily by controlled irrigation of the fertile Nile Valley; the mineral exploitation of the valley and surrounding desert regions; the early development of an independent writing system and literature; the organisation of collective projects; trade with surrounding regions in east / central Africa and the eastern Mediterranean; finally, military ventures that exhibited strong characteristics of imperial hegemony and territorial domination of neighbouring cultures at different periods. Motivating and organizing these activities were a socio-political and economic elite that achieved social consensus by means of an elaborate system of religious belief under the figure of a (semi)-divine ruler (usually male) from a succession of ruling dynasties and which related to the larger world by means of polytheistic beliefs.