Final answer:
Egypt fell under the control of the Kushyte dynasty during the 8th century BCE, following a period of civil conflict and vulnerability to foreign conquest.
Step-by-step explanation:
During the 8th century BCE, Egypt fell under the control of the Kushyte dynasty. As the New Kingdom's power waned post-1150 BCE due to a series of invasions and internal fragmentation, Egypt faced a long period of civil conflict and became vulnerable to foreign conquest. The Asyrians briefly controlled Egypt after King Taharqa's reign, but ultimate control passed to the Kushyte dynasty. The notable Kushyte king, Piye, and his successors, Shabaqo, Taharqo, and Tamwetamani, became the legitimate sovereigns forming Egypt's Twenty-fifth Dynasty. Their dynasty declined as the Asyrians renewed their interest and military campaigns leading to Egypt's fall to Asyrian might.