Most of the factors which facilitated the growth of the trans-Saharan trade were directly or indirectly related to Islam. This confirms the suggestion that Islam and the trans-Saharan trade, especially in the early period, were closely linked. The most important of these factors were the introduction of camel to North Africa, the increases in demand for gold in Muslim countries and Europe, the role of Islam, the emergence of centralised state systems in the Nigeria area and other parts of West Africa, the Islamisation of their rulers and the performance of annual pilgrimages by, especially, the rulers and the subsequent diplomatic activities which issued from them.
The trans-Saharan trade could not have been undertaken on a large-scale basis if camels had not been introduced into North Africa from Asia. The distance between Nigeria and North Africa and the Middle East was enormous, measuring hundreds of miles. Much of this was across the desert, consisting of endless and sand dunes and rocks, very hot in the day and extremely cold at night. Water could only be found in oasis situated at distant intervals. Travelling with trade goods across such hostile environment was only made possible with camels which could carry heavy loads, travel for about ten days without water and its flat hoofs enabled it to walk on the sand. It was only or mainly with camels that the dangerous journeys across the desert were undertaken.
In spite of the danger involved, the quest for gold induced many traders to participate in the trans-Saharan trade. From about the 11th century AD, gold became very important in North Africa, Europe and the Middle East. Gold was adopted as legal tender throughout the Muslim world. Its importance also increased in the 13th century when gold began to replace silver as Europe’s main currency. Between the 11th and the 17th centuries, West Africa was the leading supplier of gold to the international economy, and by the later Middle Age, West Africa provided two-thirds of the world’s gold requirements. West Africa’s gold helped the economies of North Africa, the Middle East and Europe. For this reason, large number of traders and merchants were anxious to participate in the trans-Saharan trade. Some of these traders as we have already indicated, were also Islamic scholars who wanted to preach, teach and convert people.
The spread of Islam in North Africa, the Saharan and the Sudan played important and varying roles in the expansion of trans-Saharan trade. The arrival of large number of Arabs in North Africa, the conversion of the Berbers into Islam especially in the period between the 11th and 14th centuries, the founding of states and towns in North Africa and the Sahara promoted trading activities across the Sahara. The establishment of Rustamid state of Tahert in the Sahara in 761 AD, for example, resulted in the opening up of a trade route between it and Gao on the River Niger. Muslim merchants of Arab, Berber, and probably Persian origin, soon began trading in the Sudan. The eventual conversion of the Berbers of North Africa and Sahara to Islam meant that West Africa became the most attractive source of slaves.