The Ancient Egyptian Kingdoms stopped at what was called the Great Bend. All nations throughout history only extended political and economic control as far as their transportation allowed. The Egyptians historically used the Nile River as a highway, allowing the Kingdom to govern far away regions.
The Nile River stops being useful for transportation around the Great Bend and the many cataracts in the region.
The Nile provided irrigation for farmland in an otherwise arid region. This provided the agricultural base for ancient Egypt. But how was the Kingdom politically and economically unified, rather than fragmenting in small city-states?
Empires can only hold onto political and economic regions if they can connect them through adequete transportation technology. The Egyptians used river boats on the Nile. The current flowed North to the Mediterranean Sea, while winds from the Sea blew south. So if the Egyptians wanted to transport cargo and written communications south, they raised sails on their riverboats and sailed. When they wanted to return north, they dropped the sails and floated with the current. A trip north from Thebes – near the Valley of the Kings in the center of Egypt – to Memphis near the Delta would take two weeks or so, depending on the River’s current and whether or not it was flood season. A return trip from Memphis to Thebes would take 4 to 6 weeks, depending on current and wind. This allowed the Egyptian Kingdom to create a politically and economically unified country.
Small changes in the wind direction and river’s characteristics would have limited the range of the Egyptian Kingdom to the Nile Delta.
The Egyptian Kingdoms throughout time reached their limit at the Great Bend. The bend looks like a fish hook. The Bend is an odd feature in the Nile, as seen here. The Nile normally flows north, but at the bend, it curves until it actually flows south at two different points. This is further complicated by the many cataracts – which are rocky whitewater rapids – in the River near the Bend.
Effectively, economic commerce stopped at that point. Only a few river boats could travel further south and only with great difficulty and considerable manpower. To pass through the cataracts, teams of men and ox would drag the boats from land, as seen here. Then they have another problem in the Bend. The winds do not help them travel. Indeed, they have to travel north against southernly currents and southernly wind. They must either row hard, or travel on land with ox and cart for transport.
Ancient Egypts last major cities south of Thebes were Aswan and Elephantine, near the first cataract. South of that were only two smaller cities of note at the top end of the Great Bend – the cities of El-Derr and Abu Simbel, and they were north of a series of cataracts. The Bend itself had little civilization. There were pockets of grazers, small towns of farmers, and many Nubian tribes, but the Egyptians had no political control over what is now Sudan.
The Egyptians did extend some influence across the entire Bend. South of the major cities is a string of military forts, some of the oldest on record. Nubian raids on Egypt forced the Egyptians to militarize the southern part of their country to buffer and protect their heartland. With great difficulty, the Egyptians raised armies, transported them to the Great Bend and built permanent forts. This is a string of fortifications along the entire Great Bend. The Southern most fort of Gebel Barkal at the southern point of the bend marked the limit of the Egpytian political kingdom.
Notably, the Egyptian army relied more on land-transportation that river roats along the bend. They even had to agriculturally support themselves by raising their own crops. It was relatively easy to travel back north to Egypt, but traveling south to Sudan was just to difficult.
Some of the oldest military records are found in the Great Bend region. The arid climate perserved papyrus scrolls with orders and military reports. The Egyptian military inspected Nubian traders at the border and intercepted raiders. It also appears that it made diplomatic alliances with some Nubian tribes in the region against others.
When Egyptian Kingdoms tried to expand, they could only expand North into the Mediterranean Sea where transport ships were still useful. Later Egyptian Kingdoms took interest in Palestine, Cypress, and the rest of the Eastern Mediterranean. The Sudan was beyond the reach of Egypt.