Answer: (sorry I know its long but I hope it helps)
trans-Saharan trade
Step-by-step explanation:
The Songhay state patronized Islamic institutions and sponsored public buildings, mosques and libraries. One notable example is the Great Mosque of Jenne, which was built in the 12th or 13th century. The Great Mosque of Jenne remains the largest earthen building in the world. By the 16th century there were several centers of trade and Islamic learning in the Niger Bend region, most notably the famed Timbuktu. Arab chroniclers tell us that the pastoral nomadic Tuareg founded Timbuktu as a trading outpost. The city’s multicultural population, regional trade, and Islamic scholarship fostered a cosmopolitan environment. In 1325, the city’s population was around 10,000. At its apex, in the 16th century, the population is estimated to have been between 30,000 and 50,000. Timbuktu attracted scholars from throughout the Muslim world.
The Songhay’s major trading partners were the Merenid dynasty in the Maghrib (north-west Africa) and the Mamluks in Egypt. The Songhay Empire ended when Morocco conquered the state in 1591. The fall of the Songhay marked the decline of big empires in West Africa. Merchant scholars in Timbuktu and other major learning centers dispersed, transferring learning institutions from urban-based merchant families to rural pastoralists throughout the Sahara. During this period there was an alliance between scholars, who were also part of the merchant class, and some warriors who provided protection for trade caravans. Around the 12th and 13th century, mystical Sufi brotherhood orders began to spread in the region. Sufi orders played an integral role in the social order of African Muslim societies and the spread of Islam through the region well into the 20th century.