What caused the fall of the kingdom of kush

Their food industry collapsed.

Explanation:

The farmers let their cows eat too much. The grass that once covered the soil was uprooted so the soil was free to move around, and out of the ground. This meant crops would not grow, which led to starvation. The people weakened and could not work strong jobs, like mining the precious metals. Without the crops to feed people, the trade level went low, and so did the money. The military was not as strong as it used to be, creating a chink in Kush's armor. Another contributor of Kush's downfall was Egypt's decline. Egypt was Kush's main trading partner, and because of Egypt's fall to Rome, bronze was difficult to come across. Also, other valuable items such as cedar and acacia could not be found due to the decline in money and Kush's key products. The main reason for Kush's downfall was that they could not trade and the people starved.

Rome conquered Egypt

Explanation:

The empire began to weaken after Rome conquered Egypt and eventually collapsed sometime in the 300s CE.