Egyptians sought Nubian products
In order to acquire luxury products for the pharaoh, a governor of southern Egypt named Harkhuf led several expeditions to Nubia around 2200 BC. In his tomb at Aswan Harkhuf recorded that he returned from one of his trips bringing:
300 donkeys laden with incense, ebony, oil, aromatics, panther skins, ivory carvings, boomerangs, and all good products….
The goal of Harkhuf’s expedition had been to "open the way" to the land of Yam, which lay far to the south. His return from Yam took him through three territories of Nubia—Irtjet, Setju, and Wawat—all of which, Harkhuf noted, were under the control of a single ruler. This trip, and other official Egyptian journeys, were not just trade expeditions but also military and diplomatic missions.
A line of fortifications at the 2nd cataract, like this fortress at Buhen, helped Middle Kingdom Egypt control increasing Nubian power and ambitions.
Egyptians built fortresses in Nubia
Egyptian pharaohs built a chain of fortresses along the Nile between the 1st and 2nd cataracts after they re-established central rule in Egypt around 2000 BC. Designed to protect the Egyptian frontier by controlling the region south of Aswan, the forts regulated Nubian travel and guaranteed the flow of products from southern lands, notably gold. Medjay soldiers provided a Nubian component in the forces manning Egyptian forts. Contemporary C-Group settlements found near some forts suggest close interactions, probably including trade, between the Nubians and Egyptians.