The Rock Art of Tassili n'Ajjer

The Tassili n'Ajjer is a sandstone plateau in south-eastern Algeria, part of the central Sahara. Its name in Berber means 'plateau of rivers', which is now a description of absence: the plateau is surrounded by sand, and the rivers are gone. What remains are the images painted and incised on the rock surfaces of caves, overhangs and exposed cliff faces across the range. There are thousands of them, spanning millennia, and they describe a place unrecognisable from the desert that now surrounds them.

The paintings show cattle. They show people swimming. They show hunters pursuing game, herders with their animals, groups gathered in unclear activity. They show a Sahara with enough water and vegetation to support large mammals, settled populations and the kind of life that leaves time for art. This was the African Humid Period, a span of several thousand years when increased monsoon rains turned much of the Sahara into grassland and shallow lake systems. It ended around six thousand years ago, though the drying was neither sudden nor uniform.

The art is not a single tradition. The oldest figures, assigned to the Round Head Period, are stylised and enigmatic: large-headed forms, sometimes in procession, sometimes isolated, their meaning now inaccessible. Later images are more naturalistic and more obviously tied to subsistence. Cattle dominate the Neolithic paintings, shown with the kind of individual detail that suggests familiarity. Some are dappled, some have horns that curve in specific ways, some are marked with patterns that may indicate breed or ownership. People appear beside them, often holding objects that could be ropes, staffs or tools.

Then the cattle disappear from the art, replaced by images of camels and horses. This is climate change recorded in pigment. As the Sahara dried, pastoral life based on cattle became impossible in the region. Camels, better adapted to aridity, took their place. The rock art does not document this as a single event but as a slow overwriting: camel figures painted across older cattle scenes, new images occupying the same shelters that earlier artists had used for different animals in a different climate.

The plateau itself is sedimentary rock, eroded into formations that provided shelter and vertical surfaces. The width of the range is approximately sixty kilometres, though the painted sites are scattered across a much larger area. The art is not concentrated in a single gallery but distributed across the landscape, which makes it both a archaeological site and a mountain range in its own right.

The images were made by multiple cultures over a long span. Neolithic pastoralists left the cattle. Tuareg Amazighs, later inhabitants of the region, added their own marks. The rock face became a cumulative record, each group of artists working on a surface already marked by predecessors they may or may not have understood.