1) Ancient Egypt was a highly stable civilization that lasted approximately 2500-3000 years due to its isolation along the Nile River.
2) The Nile River provided highly predictable annual flooding that made the soil fertile and supported Egypt's population with food and resources.
3) Early Egyptian society was divided into Upper and Lower Egypt that were eventually unified under the first pharaoh, Narmer. This began a long period of stable dynastic rule over a unified culture and religion.