Internal factors
- Decline in military strength: The Kushite military had been weakened by a series of campaigns against the Assyrians and other regional powers. This made them less able to defend their hold on Egypt.
- Economic decline: The Kushite economy was in decline, due in part to the disruption of trade routes and the loss of control over some of their territories. This made it difficult for them to maintain a large army and administration.
- Political instability: There was political instability in Kush, with rival factions competing for power. This led to a lack of cohesion and unity within the Kushite leadership, making it difficult for them to effectively govern Egypt.
External factors
- Invasions by foreign powers: Egypt was invaded by a series of foreign powers during the 7th century BCE, including the Assyrians and the Sais, a Libyan dynasty that had been established in the Nile Delta. These invasions further weakened the Kushite control over Egypt.
- Rise of native Egyptian nationalism: There was a growing sense of Egyptian nationalism among the native Egyptian population, who resented the rule of foreign invaders. This led to support for the Sais, who were seen as liberators from foreign rule.
In summary, the loss of control over Egypt by the Nubians (Kushites) was the result of a combination of internal factors, such as decline in military strength, economic decline, and political instability, as well as external factors, such as invasions by foreign powers and rise of native Egyptian nationalism.