The Songhay empire was based on the strength of the important trading city of Gao. This city won its independence from Mali as early as 1375, and, within a century, it had developed into an empire. Songhay carried on a vigorous trade with the outside world and particularly with the Arabic countries. The ruling class, in particular, continued to follow the religion of Islam, but it is generally believed that the masses of the population remained faithful to the more traditional West African religions based on fetishism and ancestor worship. Two of the more powerful rulers were Suni Ali, who began his 28-year reign in 1464, and Askia Mohammed, who began his 36-year reign in 1493. Askia Mohammed was also known as Askia the Great. The security of Songhay was undermined when Arabs from Morocco invaded and captured the key trading city of Timbuktu in 1591. Thus ended the last of the three great empires of West Africa. It would be a mistake, however, to assume that those parts of West Africa which remained outside of these three empires fulfilled the usual European image of primitive savagery. On the contrary, a number of other small yet powerful states existed throughout the entire period. If this had not been so, the Europeans, as they arrived in the fifteenth century, could have pillaged West Africa at will. Instead, the Europeans were only able to establish trading stations where local kings permitted it. With the exception of a few raiding parties which seized Africans and carried them off as slaves, most slave acquisition was done through hard bargaining and a highly systematized trading process. The Europeans were never allowed to penetrate inland, and they found that they always had to treat the African kings and their agents as business equals. Many of the early European visitors, in fact, were impressed by the luxury, power, trading practices, skilled crafts, and the complex social structure which they found in Africa. Only in some parts of East Africa, where the states were unusually small, were the Portuguese able to pillage and conquer at will. While many Europeans may have thought of Africa as being filled with ignorant savages, those who reached its shores were impressed instead with its vigorous civilization. The Culture of West Africa