Final answer:
Sunni Ali ruled the Songhai Empire in the 15th century, beginning around 1464 and expanding the empire's borders by conquering neighboring territories until his death in 1492.
Step-by-step explanation:
King Sunni Ali reigned over the Songhai Empire in the 15th century. His leadership began roughly in 1464 when the Songhai people at Gao rebelled against the Mali Empire, and Sunni Ali became the architect of the Songhai state. He ruled until his death in 1492, during which time he mounted a war of conquest against neighboring territories, ultimately expanding his empire significantly.
Sunni Ali's annexations, military prowess, and focus on capturing important trading centers such as Timbuktu and Djenné facilitated the growth of the empire. Although he was a Muslim, Sunni Ali's attitude towards Islamic scholars and his military campaigns against Muslim states have painted him as a controversial figure in history. Nevertheless, his reign marked the beginning of Songhai's period of expansion and dominance in West Africa before its further prosperity under his successor, Askia the Great.