What service did the west African rulers provide to encorage trade?

West African rulers facilitated trade by providing stability and security across their regions, which fostered safe travel for merchants. They also established trade routes and marketplaces, often enforcing laws that protected traders' rights and goods. Additionally, rulers sometimes engaged in diplomatic relations with other regions, enhancing trade partnerships and encouraging the exchange of goods, culture, and ideas. This supportive infrastructure helped to stimulate economic growth and prosperity in their kingdoms.