>>510691113By that standard, the Kushites were "conquered" when they were a tributary of Egypt. I suppose that "best point in their relationship" would be a period where:
1. Both Egypt and Kush maintained their independence from each other
2. They were not at war with each other or otherwise in direct conflict
3. They cooperated with each other in some voluntary manner (such as trade).
I guess that means the apex of Egyptian-Kushite relations would have been during the Ptolemaic Dynasty?