What was the background of the slaves who were taken to european forts along the african coast to be traded in the mid-sixteenth century?

The slaves came from villages in Africa which had been raided or captured by stronger groups

there were abundant sources of fuel nearby

judaism, christianity and islam, are all abrahamic religions and therefore have in common the hebrew idea of a single god which is the source of all morality. the idea of the covenant is only related to judaism, while dharma is a concept of indian religions and the four noble truths are basic principles of buddhism.