Neil Faulkner looks at the early civilisations in Africa and how geography ensured the continent would develop differently from Eurasia.

Eurasia is a gigantic east-west thoroughfare stretching for 6,000 miles across the surface of the Earth. For thousands of years, people and ideas have moved up and down this thoroughfare, and up and down its many byways.

Because Eurasia is aligned east-west, thoroughfares are formed by its uniform climatic zones. In particular, the Eurasian steppes, a belt of grassland hundreds of miles deep, run almost unbroken from the Carpathians to the Pacific. Along this great corridor came the Aryans, the Huns, the Turks, and the Mongols. Down its byways spilled Greeks, Celts, Goths, and Slavs.

Traders, invaders, and settlers carried ideas across Eurasia’s many routeways. When they did so, because of uniform climate zones, what worked in one place also worked in others. All the great domesticates of the Agricultural Revolution – barley, wheat, and rice; cattle, sheep, goat, pigs, and hens – were transferable.

Africa was different. Africa runs north-south for 4,000 miles. As it does so, it passes great barriers and several climatic zones: from north to south, coastal plain, desert, savannah, tropical forest, savannah, desert, and coastal plain.

The desert and the forest are barriers to movement and un-amenable to farmers. There is also disease, above all that borne by the tsetse fly, which feeds on the blood of humans and animals. And, for all its variety and exoticism, the African fauna does not include a disease-resistant traction animal strong enough to pull the plough.

Geography determined that Africa would develop differently from Eurasia. Constraints were greater, opportunities fewer. Africans were as creative as any other humans – as capable of great art, architecture, and engineering as Romans, Arabs, and Chinese. But geographical barriers prevented them building great imperial civilisations.

The advance of farming was slow and patchy. Sub-Saharan Africa had no equivalent of the Nile Valley or Mesopotamia, the Indus or the Ganges, the Yellow or the Yangtze; no giant bread-baskets able to sustain an empire.

On the other hand, ancient rock-carvings in the Sahara depict men herding cattle and driving two-wheeled chariots. From about 1000 BCE to 600 CE, the trans-Saharan trade routes linked West Africa to the Mediterranean and began its transformation.

Sub-Saharan Africa traded gold, iron, slaves, salt, and ivory, all in growing demand in the Mediterranean. Back down the trade routes came knowledge of ironworking and cattle husbandry.

In the development of West Africa, the River Niger was the vital line of communications for the movement of trade goods and ideas. Running west-east, it forms a gigantic curve through the whole region, linking savannah, forest, and coast, while many large tributaries spread the influence of river-borne culture deep into the West African hinterland.

Iron, cattle, and trade along the River Niger were the basis of the Nok culture of Nigeria (c. 500 BCE-200 CE). Iron-working began as early as c. 450 BCE, and African smiths were soon pioneering new techniques and forms. At the same time, African potters were demonstrating exceptional artistic skill in the fashioning of life-size terracotta heads.

Mediterranean civilisation continued to act as an indirect catalyst of West African development, and as the demand for high-value commodities grew, larger surpluses could be accumulated. These created the basis, first, for trading towns, and later, for trading states.

Jenne-Jeno, on an island in the Niger, was surrounded by a 2km-long wall of cylindrical blocks between 400 and 800 CE. Inside was a town of round and rectangular mud-brick houses. When Arab-Muslim traders arrived in the 8th century CE, towns already existed in West Africa.

So did a major trading state. The Kingdom of Ghana, established around 600 CE, controlled the Niger Delta. At its peak, its territory extended for 800km across West Africa, and the Arabs called it ‘the land of gold’.

Other parts of Africa had also spawned civilisation. The Kushites or Merowites controlled much of the Upper Nile (modern Sudan) between c. 900 BCE and 325 CE, maintaining their independence against Egyptian, Hellenistic, and Roman threats.

The Kushites were eventually overthrown by the Ethiopians. The small Red Sea trading state of Axum had grown from c. 50 CE into the Horn of Africa’s major regional power. Later, though contained by the Arabs, the Ethiopian state would survive as an Early Christian enclave in an otherwise Muslim region, notable for spectacular rock-cut churches.

But West Africa was the powerhouse. It was from here that iron and cattle were spread across the continent. The agents of transmission were Bantu-speaking migrants. Their folk-movements reached into East Africa and the Lakes during the half millennium after 500 BCE, then deep into Southern Africa during the subsequent half millennium.

Ancient and medieval Africa was an extreme example of what has been called ‘combined and uneven development’. For one thing, hunter-gatherers, cattle-pastoralists, and slash-and-burn cultivators coexisted: African geography prevented the dominance of any one mode of production. For another, under foreign influence, Africa made the leap direct from the Stone Age to the Iron Age: there was no intermediate Bronze Age.

Between the 8th and 12th centuries CE, Arab influence spread across Africa. They traded with West Africa both north-south across the Sahara and east-west across the savannah belt to its south. Towns like Timbukto grew rich on the Arab trade. They also established a string of trading settlements, like Kilwa, along the coast of East Africa.

Again, Africa changed in response to foreign impact. And again, once responding, Africa revealed the creativity and dynamism of its own people.

Between 1200 and 1750 CE, a succession of trading states rose and fell in West Africa – Mali, Hausa, Benin, Kanem-Borno, Songhay, Akan/Ashanti, and others – while in Central-East Africa, the stimulus provided by coastal trade produced the civilisation of Great Zimbabwe.

The Benin civilisation of the Niger Delta produced bronzework of the highest standards, its famous bronze-heads reminiscent of the terracottas of the Nok Culture. They are admired today as among the greatest masterpieces of medieval art.

Great Zimbabwe is renowned for its architecture. The Great Enclosure was the largest building in sub-Saharan Africa at the time, comprising a wall roughly 250m long, 5m thick, and 10m high.

The wealth of the rulers of Great Zimbabwe was based on cattle and on the trade with the coast in gold, iron, copper, and tin. The pattern was the same as in Benin and other West African states.

Geographical constraints limited the surpluses that could be accrued from agriculture. All of Africa’s many ‘urban revolutions’ depended on trade.

From 1000 BCE to the coming of the Europeans from the 15th century onwards, the main lines of African social development were contingent on the activities of others. Geography condemned Africa to dependent status.