Ancient Egyptian merchants plied the waters of the Nile and the Red Sea to trade with distant lands. But archaeological evidence suggests that overland routes - previously given little attention - were of equal importance in trade with kingdoms such as Aksum, Nubia, and Punt.

"Trade has long been the subject of discussion, mainly attempts to ascertain ancient Egyptian contacts with other peoples who inhabited the farther reaches of the ancient known world and, more importantly, their luxury goods that Egypt acquired," says Jacke Phillips of the McDonald Institute for Archaeological Research at the University of Cambridge, England.

Contact with Punt, to the southeast, has long focused on the Red Sea route, while contact with Nubia, to the south, has centered on the Nile. Although historical documents and some archaeological evidence has pointed to the existence of overland routes linking these water-based Nile and Red Sea routes - particularly through the eastern desert of Egypt and others leading to quarrying and mining areas - overland routes south of Egypt have been little studied. Although the overland network is not well understood, it is known to have existed by at least the Neolithic period, says Phillips.

Goods such as cowrie shells (a Red Sea import) have been found in graves along the Nile Valley as far back as the Neolithic period in Nubia and Egypt. Obsidian, another import, also points to such a trade network. Further analysis would help pinpoint the exact sources of these materials.

Nearly 200 Egyptian potsherds - dating to the late Middle and early New Kingdom - were found in eastern Sudan near Khartoum and point to Egyptian association with this route. Excavations in northern Ethiopia have revealed statues with possible Egyptian influence. At Haulti, Ethiopia, excavators found a couple of Egyptian faience figurines - a glass-related technique - of Isis and Ptah. "The scale of this contact must have been considerable throughout the first millennium B.C. and must also have continued into the period A.D.," states Phillips.

Phillips says that historical evidence of such routes can be found in documents such as that of an early Egyptian expedition leader named Harkhuf, who wrote in his autobiography of exploring overland routes from the Nile east on the mountain paths to Irtjet by donkey and trading exotic goods even further east.

Furthermore, the existence of quarrying and mining sites in inhospitable areas far into the eastern desert of Nubia - where workers could be sustained only by regularly transporting their food and drink from sources at long distances - demonstrates that the areas between the Red Sea and Nile Valley were well traveled.