Diplomacy played a key role in interactions between leaders, and trade brought many foreigners into contact with the Egyptians.
Egypt lies at the crossroads between Africa and Asia. Though the Egyptians built fortresses at their borders to control the movement of people and goods, immigration occurred frequently.
Many foreign groups, including Nubians and Libyans settled in Egypt over time. Once a person adopted Egyptian ways (often including an Egyptian name), they were regarded as Egyptian. In this manner, the Egyptians were very open to immigration.
Later in history, when Egypt was ruled by Macedonian Greek kings, traditions were exchanged, so that mummies were decorated with a realistic rather than stylistic depiction of the deceased. They could be as a two dimensional painting on wood or a three dimensional representation in stucco.
Egypt similarly influenced the beliefs of neighbouring cultures, especially in Nubia, which adopted and developed some aspects of Egyptian culture.