How did Egypt lose control over Kush?

Egypt lost control over the region of Kush due to a combination of factors including political instability, economic pressures, and military challenges.

1. Political Instability: The New Kingdom of Egypt, which had control over Kush in the beginning, went into decline around 1070 BCE. This time period saw frequent changes in dynasties and struggles for power in Egypt. The internal conflicts weakened the state's ability to maintain control over distant territories like Kush.

2. Economic Pressures: The administration and military expeditions in distant lands like Kush were very costly for Egypt. As resources became scarcer and priorities shifted, maintaining a firm grip on Kush became less feasible.

3. Military Challenges: During the later end of Egyptian control over Kush, there were increased incursions and pressures from other peoples and invaders such as the Assyrians. This forced Egypt to focus its military efforts elsewhere, leaving Kush more autonomous.

4. Rise of Kush: Eventually, the kingdom of Kush, centered in Napata at the time, grew stronger and more organized, with its leaders becoming more assertive. The Kushite kings capitalized on the weakening Egyptian control and declared their independence.

5. Kushite Kings Take Over: After gaining independence, the Kushite kings, notably King Kashta and his successor Piye (Piankhi), extended their power northward, actually conquering Egypt and ruling it for a short period during the 25th dynasty. This period is a demonstration of how completely control had shifted away from the Egyptians to the Kushites.