Why is Upper Egypt southern and Lower Egypt northern?

(The upper and lower refer to the river course.) Because the Nile flows NORTHWARD from equatorial Africa , the "Upper Nile" is the southern end and "Lower Nile" the northern end, where its delta meets the Mediterranean Sea. The "White Nile" is created by the feeder rivers of Lake Victoria in Uganda, while the "Blue Nile" begins in Ethiopia above Addis Ababa. The two Niles flow together some distance north, at Khartoum in Sudan. "LOWER EGYPT" is the name applied to the Nile Delta north of Dahshur (just upriver from Cairo). "UPPER EGYPT" refers to the cataract region downriver from Sudan.