query: When did ancient Egypt begin?
passage: History of ancient Egypt
The historical records of ancient Egypt begin with Egypt as a unified state, which occurred sometime around 3150 BC. According to Egyptian tradition, Menes, thought to have unified Upper and Lower Egypt, was the first king. This Egyptian culture, customs, art expression, architecture, and social structure was closely tied to religion, remarkably stable, and changed little over a period of nearly 3000 years.
passage: History of agriculture
The civilization of Ancient Egypt was indebted to the Nile River and its dependable seasonal flooding. The river's predictability and the fertile soil allowed the Egyptians to build an empire on the basis of great agricultural wealth. Egyptians were among the first peoples to practice agriculture on a large scale, starting in the pre-dynastic period from the end of the Paleolithic into the Neolithic, between around 10,000 BC and 4000 BC.[52] This was made possible with the development of basin irrigation.[53] Their staple food crops were grains such as wheat and barley, alongside industrial crops such as flax and papyrus.[52]