Why was manetho so important to the Nubian's and Egyptian's?

Manetho was important to the Nubians and Egyptians because he was an ancient Egyptian priest and historian who documented the history of Egypt in the 3rd century BCE. His work, "Aegyptiaca," provided a chronological framework for understanding Egyptian dynasties, which was crucial for both preserving Egyptian heritage and facilitating Nubian relations with Egypt. By organizing Egyptian history into dynasties, he helped establish a sense of national identity and continuity, shaping how both Egyptians and Nubians viewed their past and each other. His writings also influenced later historians and contributed to the understanding of ancient Egyptian civilization.