The Mountains of the Moon and the Sources of the Nile

The Mountains of the Moon are one of the most consistent and enduring apocryphal elements in the history of cartography. Cartographers mapped the Mountains of the Moon and two or three associated lakes as the source of the Nile River from the 14th to the early 19th century. We always found it remarkable that this one feature was consistently mapped in the otherwise blank or speculative interior of Africa. From whence did it come?

The source of the Nile River has been a matter of speculation for thousands of years. The ancient Greek historian Herodotus was probably the first to compile and record the various theories of the river’s origins. According to Herodotus, the Ancient Egyptians believed that the Nile had its source in two great mountains within which were eternal springs. From here one branch was said to flow north, dividing Egypt, and another south into Nubia and Ethiopia. The priests of Sais, from whom Herodotus extracted this theory, believe the mountains to lie somewhere between Thebes and Elephantine (Aswan). Cleary, even in Herodotus’ day, the Nile had been explored well into Nubia and this was generally known to be false.

Herodotus also mentions several other theories, one of which we shall mention here. It was believed by some that the Nile River’s annual inundation was caused by snowfall at its source. Herodotus spurned this theory based upon the well known fact that, as one travels south towards the equator it becomes excessively hot. In Herodotus’ day it was believed that the temperatures in the Torrid Zone, as it was called, where so severe and the beasts that dwelt there so ferocious, that the region was all but impassable. How, Herodotus asked, could there be snows in such a place? Despite being wholeheartedly dismissed by Herodotus, this theory is very close to the truth.

Actual course of the Nile River.

Actual course of the Nile River.

Before moving forward with the next major figure in this story, it is perhaps prudent to describe the actual course of the Nile River. Traveling against the Nile’s current, one would head directly south for many thousands of miles, passing through Egypt and Sudan before coming to a divide near the modern city of Khartoum or ancient Meroe.

Coronelli's Map of the Source of the Nile

Coronelli's 1690 Map - the first to show the source of the Blue Nile in Ethiopia.

Following the eastern branch of the river, the Blue Nile, one would travel in a southeasterly direction into modern day Ethiopia, where the river makes a dramatic bend of some 100 miles to the point where it flows southwards from Lake Tana. North of Tana are the spectacular Simian Mountains. One of the highest ranges in Africa, the Simians are one of the few places on the continent to receive significant and regular snowfall. A modern giordano libero traveler to the Simians may be disappointed with the snow – global warming – but inscriptions dating to the 6th century (the Adulite inscription) record how military campaigns marching through the region were knee deep in snowfall.

The other branch of the Nile, the White Nile, splits off to the southwest. Following this branch will eventually lead to Lake Victoria. Victoria is at the base of the Rwenzori Mountains. The Rwenzori, which means “maker of rain” in local dialects, are a small but dramatic range just to the northwest of Lake Victoria. These mountains, like the Simians, experience regular and significant snowfall. They also hold several significant glaciers. Today these are among the most endangered glacial formations on the planet. This region is also one of last surviving habitats for the rare endangered Mountain Gorilla.

Ptolemy's Source of the Nile

Ptolemy's Source of the Nile

Back to our story. The next major compiler of information on the interior of Africa was the 2nd century Alexandrian geographer Claudius Ptolemy. The influence of Ptolemy on the cartographic tradition cannot be understated and lasted well into the modern era. Ptolemy’s Geographica consisted of several books accompanied by maps. Unfortunately Ptolemy’s original maps are lost to us today though mediaeval copies do exist. Ptolemy compiled his geography of Africa based on the writings of Marinus of Tyre. Marinus recorded that around 50 CE the Greek trader Diogenes traveled inland from Rhapta (coastal city in what is today Tanzania) for 25 days before encountering two great lakes and a snowy range of mountains where the Nile draws its source (Lane-Poole 1950: 4).

Though there is some debate on this subject, it seems very clear that Diogenes, traveling directly west from the coast, came upon either Lake Nyassa or Lake Victoria (or both). The nearby snowcapped mountains could only be the Rwenzori range. Others have suggested that Diogenes may have spotted Kilimanjaro, however, this is unlikely given the absence of a major lake in the region as well as that that Diogenes described a range rather than a solitary mountain. In any case, via Marinus’s writings, the travels of the Greek merchant Diogenes found their way into to Ptolemy’s canonical Geographica and we see the first appearance of the Mountains of the Moon.

With such a provocative name, the “Mountains of the Moon”, one must wonder from whence it was derived. There is some speculation (in fact the only we’ve come across) that this is a transliteration into Greek of the Amharic name for the mountains near Lake Tana at the source of the Blue Nile, called to this day, the Simians. In Amharic, “Simian Mountains” translates as “Northern Mountains”. However, a liberal transliteration of the word “Simian” into Greek might come up with “Selene” – the Moon Goddess.

How, one wonders, did the Simian Mountains get confused with the Rwenzori Mountains thousands of miles away? One must remember that Ptolemy was piecing together very sparse second and third hand accounts of merchant voyages, military campaigns, ancient Egyptian records, etc. The southernmost inland city in Africa in Ptolemy’s Geography is Axum in Ethiopia. Lake Tana and the Simien Mountains were still a significant distance further south. Nor are Ptolemy’s coordinates necessarily accurate with regard to latitude. Nor would Ptolemy, more familiar with the great mountain ranges of Europe and Asia, have been familiar with the small but dramatic mountain ranges of Africa. It is not hard to imagine how, from this perspective, two mountain ranges, relatively close, both associated with lakes, and both associated with the source of the Nile, might be assumed to be one and the same. It is thus likely the he simply applied the known name, Simian-Selene, to all mountains associated with the Nile’s source.

In the 4th Century CE, Ethiopia converted to Coptic Christianity. From this critical point onward, regular communication between the Ethiopian Orthodox church and the Coptic centers in Egypt provided the first accurate maps of Ethiopia. Consequently, by the time cartographers in the Middle Ages began translating Ptolemy’s surviving texts and interpreting them into maps, the source of the Blue Nile was known. Though Ptolemy does not specifically note the presence of Lake Tana, it is mapped in even the earliest medieval interpretations of Ptolemy’s work. Thus by the time the first European maps of Africa were being drawn, the mystery of the Blue Nile’s source been solved.

Which left the more mysterious White Nile. Drawing from Ptolemy, cartographers repositioned the Mountains of the Moon and their lakes further south – where they remained until the 19th century. In the late 18th century many cartographers, including such luminaries as Anville and De L’Isle, chose to remove either the Mountains of the Moon, the Lakes of the Nile, or both from their maps of the region. It was not until the exploration of John Speke and Henry Morton Stanley in the mid 19th century until these lakes ultimately reappeared and Ptolemy’s not so apocryphal geography of the Nile was proven eerily correct.

G.W.B. Huntingford, Periplus of the Erythraean Sea, p. 175 (London: the Hakluyt Society, 1980).
Ralph Ehrenberg, Mapping the World : An Illustrated History of Cartography (National Geographic, 2005)
William Desborough Cooley, Claudius Ptolemy and The Nile . . . (London, 1854).