The Sahara is the largest non-polar desert in the world, covering almost 8,600,000 km² and comprising most of northern Africa, from the Red Sea to the Atlantic Ocean. Although it is considered a distinct entity, it is composed of a variety of geographical regions and environments, including sand seas, hammadas (stone deserts), seasonal watercourses, oases, mountain ranges and rocky plains. Rock art is found throughout this area, principally in the desert mountain and hill ranges, where stone ‘canvas’ is abundant: the highlands of Adrar in Mauritania and Adrar des Ifoghas in Mali, the Atlas Mountains of Morocco and Algeria, the Tassili n’Ajjer and Ahaggar Mountains in Algeria, the mountainous areas of Tadrart Acacus and Messak in Libya, the Aïr Mountains of Nigeria, the Ennedi Plateau and Tibesti Mountains in Chad, the Gilf Kebir plateau of Egypt and Sudan, as well as the length of the Nile Valley.
Types of rock art and distribution
Although the styles and subjects of north African rock art vary, there are commonalities: images are most often figurative and frequently depict animals, both wild and domestic. There are also many images of human figures, sometimes with accessories such as recognisable weaponry or clothing. These may be painted or engraved, with frequent occurrences of both, at times in the same context. Engravings are generally more common, although this may simply be a preservation bias due to their greater durability.
The physical context of rock art sites varies depending on geographical and topographical factors – for example, Moroccan rock engravings are often found on open rocky outcrops, while Tunisia’s Djebibina rock art sites have all been found in rock shelters. Rock art in the vast and harsh environments of the Sahara is often inaccessible and hard to find, and there is probably a great deal of rock art that is yet to be seen by archaeologists; what is known has mostly been documented within the last century.
History of research
Although the existence of rock art throughout the Sahara was known to local communities, it was not until the nineteenth century that it became known to Europeans, thanks to explorers such as Heinrich Barth, who crossed the Messak Plateau in Libya in 1850, first noting the existence of engravings. Further explorations in the early twentieth century by celebrated travellers, ethnographers and archaeologists such as Hassanein Bey, Abbé Breuil, László Almásy, Henri Lhote and Leo Frobenius brought the rock art of Sahara, and northern Africa in general, to the awareness of a European public.
Attribution and dating
The investigations of these researchers and those who have followed them have sought to date and attribute these artworks, with varying measures of success. Rock art may be associated with certain cultures through known parallels with the imagery in other artefacts, such as Naqada Period designs in Egyptian rock art that mirror those on dateable pottery. Authorship may be also guessed at through corroborating evidence: for example, due to knowledge of their chariot use, and the location of rock art depicting chariots in the central Sahara, it has been suggested that it was produced by – or at the same time as – the height of the Garamantes culture, a historical ethnic group who formed a local power around what is now southern Libya from 500 BC–700 AD. However, opportunities to anchor rock art imagery in this way to known ancient cultures are few and far between, and rock art is generally ascribed to anonymous hunter-gatherers, nomadic peoples, or pastoralists, with occasional imagery-based comparisons made with contemporary groups, such as the Fulani peoples.
Occasionally, association with writing in the form of, for example, Libyan-Berber or Arabic graffiti can give a known dating margin, but in general, lack of contemporary writing and written sources (Herodotus wrote about the Garamantes) leaves much open to conjecture.
Other forms of (rare) circumstantial evidence, such as rock art covered by a dateable stratigraphic layer, and (more common) stylistic image-based dating have been used instead to form a chronology of Saharan rock art periods that is widely agreed upon, although dates are contested. The first stage, known as the Early Hunter, Wild Fauna or Bubalus Period, is posited at about 12,000–6,000 years ago, and is typified by naturalistic engravings of wild animals, in particular an extinct form of buffalo identifiable by its long horns.
A possibly concurrent phase is known as the Round Head Period (about 10,000 to 8,000 years ago) due to the large discoid heads of the painted human figures. Following this is the most widespread style, the Pastoral Period (around 7,500 to 4,000 years ago), which is characterised by numerous paintings and engravings of cows, as well as occasional hunting scenes. The Horse Period (around 3,000 to 2,000 years ago) features recognisable horses and chariots and the final Camel Period (around 2,000 years ago to present) features domestic dromedary camels, which we know to have been widely used across the Sahara from that time.
While this chronology serves as a useful framework, it must be remembered that the area – and the time period in which rock art was produced – is extensive and there is significant temporal and spatial variability within and across sites. There are some commonalities in rock art styles and themes across the Sahara, but there are also regional variations and idiosyncrasies, and a lack of evidence that any of these were directly, or even indirectly, related. The engravings of weaponry motifs from Morocco and the painted ‘swimming’ figures of the Gilf Kebir Plateau in Egypt and Sudan are not only completely different, but unique to their areas. Being thousands of kilometres apart and so different in style and composition, they serve to illustrate the limitations inherent in examining northern African rock art as a unit. The contemporary political and environmental challenges to accessing rock art sites in countries across the Sahara serves as another limiting factor in their study, but as dating techniques improve and further discoveries are made, this is a field with the potential to help illuminate much of the prehistory of northern Africa.