Sofas make their first appearance in oral and written records during the formation of the Mali Empire. Sofas were recruited from "jonow" (slaves) captured in battle or bought from afar. They could be depended on in most instances for obedience, since their livelihood depended entirely on their master. The institution of slavery in the Mali Empire heavily rewarded loyalty, and jonow could rise to civil or military positions of prominence. Jonow became part of their master's clan, and were often freed after a certain number of years.