Culture clash
Egypt and Nubia were close neighbors who fought for many centuries. Sometimes the battle was over trade, gold, or political power.
Egypt was stronger than Nubia for a long time, and they conquered Nubia and took its valuable resources. However, Nubia became independent and developed its own society and traditions.
During the Late Kerma part in Nubian history. Egypt was conquered by the Hyksos; the Egyptians hated them. But, Nubia made agreements with them, which resulted, in the Hyksos leaving Nubia alone, But the Egyptians got mad at the Nubians.
Then a powerful ruler, called Ahmose, came to the throne, then he conquers the Hyksos and expelled them from entering Egypt. Then he redirected his anger on the Nubians. He decided to occupy Nubia because the Nubian’s relationship with the Hyksos was a threat to Egypt.