In a remote corner of Sudan, a little-known site holds clues to the prehistoric climate change that created the world’s largest desert
Our pickup truck turned onto a dusty two-track road heading away from the Nile River in north-eastern Sudan. Ahead of us, the landscape stretched forever and the small bumps on the horizon, perhaps distant mountains or nearby sand dunes masked by mirage, were impossible to gauge in the vastness. The only thing that appeared certain was the emptiness.
After an hour, we arrived at a wadi (dry riverbed) lined with outcrops of crumbling sandstone. Daydreaming as soft tunes of Sudanese jazz crackled through the staticky radio, I snapped back to attention as something caught my eye: a white animal-like shape on one of the cliff faces. Wondering if it was the desert playing tricks on me, my doubts dissipated when we rounded a corner and stopped. Surrounding us, on every exposed surface of rock, were thousands of ancient petroglyphs depicting scenes of elephants, giraffes, ostriches and boats.
As an archaeologist who has worked on projects from the bottom of the Black Sea to the tops of the Rocky Mountains, it’s not every day that a site completely surprises me
As the wind picked up and the sand began to blow, I stared in awe at the unexpected scenes depicting what I’d imagine to see in the lush grasslands and winding waterways of the Serengeti, but not in the bone-dry Nubian Desert, the eastern flank of the Sahara sandwiched between the Nile and the Red Sea. As an archaeologist who has worked on projects from the bottom of the Black Sea to the tops of the Rocky Mountains, it’s not every day that a site completely and utterly surprises me. However, this veritable encyclopaedia of petroglyphs etched in front of me marked a rare and exciting exception.
“Welcome to Sabu,” said my driver with a smile, “where you can see how Sudan used to be.”
The climate of the Sahara region was once drastically different than it is today
Hidden amongst rock outcrops between the third and fourth cataracts of the Nile River, the archaeological site of Sabu-Jaddi (or simply “Sabu”) contains more than 1,500 rock drawings spanning 10,000 years of human history in the region. Archaeologists have yet to determine when, exactly, the ancient Nubians who lived here first chiselled these images, but one thing is for sure: the remarkably well-preserved etchings of hippos, crocodiles and papyrus boats depict a vastly different world than the parched desert landscape that now covers much of northern Africa, and offer a glimpse into the Sahara’s verdant past.
“Sabu has a large diversity of figures,” said archaeologist Dr Bruce Williams, who worked in Sudan for more than 50 years. “There are animals from early times, cattle from the later Kerma period (2600-1450BC), boats of Egypt’s New Kingdom (1570-1069BC), a collection of Christian period motifs and more that continue through time.”
Beyond the sheer magnitude of drawings and the deep history that the site encompasses, Sabu also provides a detailed record of how people lived and adapted as the world’s largest desert began to form around them.
The climate of the Sahara region was once drastically different than it is today. Though the desert is generally considered to be two to three million years old, during a time known as the African Humid Period (roughly 13000-3000BC), seasonal monsoons from Central Africa swept upwards, delivering ample rainfall to the northern part of the continent. During this era, the Nile surged as it was fed by countless rain-filled tributaries that snaked into a green, fertile plain – much like the savannahs of Kenya and Tanzania. Immense herds of elephants, giraffes and gazelles thundered across the landscape and hippos snorted throughout ponds and riverways. A large variety of plants and animals offered abundant resources to humans who roamed these grasslands in small family groups of hunter-gatherers.
At Sabu, the hundreds of animal figures that were incised into the sandstone’s surface are evidence of this forgotten era. This earliest form of Saharan rock art is known as the Bubaline Phase, and while Sabu isn’t the only site with ancient petroglyphs depicting exotic game animals in the Sahara, it was the first in Sudan to be documented (by a British archaeological expedition in the 1940s) and remains one of the only ones readily accessible to visitors today.
“There is a lot of rock art in Nubia and the adjacent deserts,” explained Dr Williams. “Most big outcrops, especially those with caves, are often spectacularly developed.” While the imagery is widespread across Sudan, Sabu remains one of the largest known concentrations in the country.
Beyond the ancient art, other information about prehistoric people’s relationships with animals has been identified at nearby excavations, where butchered bones from warthogs, leopards, monitor lizards, fish, gazelles and giraffes lie alongside remnants of chipped stone tools and ancient fire hearths. The evidence of such game, both at Sabu and in the nearby excavations, offers a glimpse into a time when life on the grassy North African plains was ample. But it was not to last, and around 5500-5000BC, the climate began a 2,000-year transformation as the African Humid Period slowly came to an end.
As I continued my exploration at Sabu, venturing deeper into the site, climbing over large sandstone boulders and squeezing through cracks in the cliffside, other creatures began to appear among the traditional animals of the African plains. One in particular, suddenly visible everywhere I looked, stood out among the exotic: the common cow. The appearance of the humble bovid (which marks a new artistic period in the Sahara, known by rock art historians as the Bovidian Phase), while perhaps not as incongruous as an elephant or ostrich, is evidence of an important societal shift that was likely initiated by the changing climate 7,000 years ago.
When the humid weather patterns of North Africa began to shorten as seasonal monsoons became less frequent, both people and animals migrated closer to the banks of the Nile. As the weather continued to dry, the humid period came to an end, and by 3500BC the Sahara we are familiar with today was formed.
Perhaps in response to this climatic change, the mobile hunter-gatherers of the region gradually became more sedentary and increasingly relied on domesticated animals such as cows, sheep and goats, which grazed near watering holes. This cultural shift to pastoralism is often used to define the early start of the Neolithic Period, and a trajectory that would eventually evolve into farming and the creation of permanent villages, towns and kingdoms. During this time, the importance of cattle increased exponentially and became a focal point for trade and economy in Sudan.
To Swiss archaeologist Jérôme Dubosson, the prevalence of cow figures at Sabu helps us understand the significance that these animals would come to have throughout Sudan. For instance, at the nearby historical capital of the ancient Kushite Kingdom, Kerma, the skulls from thousands of sacrificed cattle were buried in tombs dating to 2000BC. The increase in cattle both in rock art and at other excavations reveals a shift in economy and a picture of how people adapted to the changing desert conditions. This new pastoral lifestyle would become characteristic of desert societies throughout northern Africa, outliving the rise and fall of Sudan’s Kushite kings and Egypt’s pharaohs.
Pastoralism has remained an integral part of desert life in Sudan, and several indigenous nomadic tribes such as the Hasania and neighbouring Bisharin continue to roam the arid landscape herding goats, sheep and camels in addition to their once-omnipresent cows. By moving with their animals across a large territory, the nomadic lifestyle has allowed them to persevere in the harsh desert that exists where a lush savannah once stood.
Similarly, rock art continues to retain its importance among modern Nubian nomads, and etchings representing camels, Arabic sayings and even the occasional car and bus can be found layered among the more ancient drawings. After millennia, Sabu maintains its role as the region’s diary, its quiet ravine offering a place for memories to be inscribed and preserved.
While the surrounding rocks have quietly observed the desert’s slow transformation, a new change is currently underway that may once again impact the lives of those who call the Sahara home.
A few days after visiting Sabu, I sat in a hut built from branches and covered by brightly covered fabric that gently muffled the sounds of a half-dozen camels and goats outside. Taking a sip of freshly roasted coffee spiked with spicy ginger, I listened to Medina, a 98-year-old Hasania nomad, as she spoke softly about her life in the remote desert of northern Sudan. As a child, she remembered when the British arrived demanding taxes from the tribes, and when the first roads were built across her people’s territory, which encouraged many nomads to settle into houses for the first time.
When I asked what the future may hold for northern Sudan, she spoke of rain. She explained that she and her family have noticed a shift in weather patterns and they wonder how it will affect them. I sat in awe, listening as this elderly nomad, living in complete isolation from news and mass media, expressed her observations and concerns about climate change and how it might once again alter the landscape of the great desert.
As our pickup truck rattled away from the encampment and towards the Bayuda Desert below the great Bend of the Nile, Medina’s words remained in my mind. Much as it has done for thousands of years, the desert is continuing to shape the lives and culture of those who live within it. Staring out of the window and allowing myself to be enveloped by the vastness outside, I wondered what kinds of figures would be engraved next into the sandstone diary of Sabu, and what tales they will portray to future travellers down the road