The Songhai Empire strengthened Islam by encouraging the spread of Islamic teachings and culture. The rulers of the Songhai Empire were devout Muslims and they actively promoted the religion by building mosques, appointing Islamic scholars to teach in schools, and encouraging the study of Islamic law. They also encouraged trade with other Muslim countries, which helped to spread the religion even further.

In addition to promoting Islamic teachings and culture, the Songhai Empire also incorporated Islamic practices into their governance and administration. The rulers adopted Islamic titles and symbols of authority, such as the caliphate system, and implemented Islamic customs and laws in their legal systems.

The Songhai Empire's promotion of Islam also extended to military campaigns. The rulers would often invoke jihad, or holy war, to justify their territorial expansion, furthering the spread of Islam in the regions they conquered. As a result, the empire became a major center of Islamic scholarship and attracted scholars and students from across the Muslim world.

Trade played a crucial role in strengthening Islam within the Songhai Empire. The empire's control over the lucrative trans-Saharan trade routes allowed for the exchange of goods, ideas, and religious teachings. Muslim traders traveled to and settled in the empire, contributing to the dissemination of Islamic beliefs and practices.

The Empire's capital, Gao, became a hub of Islamic intellectual and cultural exchange. Timbuktu, a key city in the empire, developed into a prominent center of Islamic learning. The University of Sankore, one of the leading educational institutions in the Muslim world at the time, attracted scholars from various backgrounds and facilitated the spread of Islamic knowledge.

Overall, the Songhai Empire's rulers actively promoted Islam through various means, including the construction of religious buildings, the patronage of scholars, the incorporation of Islamic practices into governance, and the facilitation of trade with other Muslim states. These efforts significantly strengthened the influence and presence of Islam within the empire.