Mansa Mahmud Keïta IV, also known as Niani Mansa Mamadou, was the last reigning emperor of the Mali Empire according to the Tarikh al-Soudan in the 17th century. His reign is notable for the period of continuous decline of the Mali Empire, once one of the most powerful and wealthy empires in West Africa. Before his reign, there was a sort of power vacuum, indicated by the long period during which neither written nor oral sources provide information about a leader. It is known that more than one person from the Keïta family claimed the throne of Manden Massa. Due to the succession law that was open to various branches of the family, many disputes led to dissensions that weakened the power of the Mansa. This, in turn, caused the Sankar-Zouma and Farima-Soura to refuse any assistance to Mansa Mahmud IV and the Keïta family in their military campaign against Djenné. It is highly likely that his father was the previous Mansa, known as Mansa Namaghan, who ruled between 1559 and 1590.
See main article: Battle of Jenne. Mansa Mahmud Keita IV launched an attack on the city of Djenne in 1599 with Fulani allies, hoping to take advantage of the Songhai Empire's defeat. Moroccan fusiliers, deployed from Timbuktu, met them in battle, exposing Mali to the same technology (firearms) that had destroyed Songhai. Despite heavy losses, the mansa’s army was not deterred and nearly prevailed;[1] however, the army inside Djenne intervened, forcing Mansa Mahmud Keita IV and his army to retreat to Kangaba.[2] Mandinka oral history says that the three sons of Mahmud IV divided the kingdom and fought amongst themselves.