THE SONGHAI EMPIRE
Capital, Gao, established the beginning of the 11th century with Dia (King) Kossoi, a Songhai convert to Islam.
Gao prospered for 300 years, getting added into Mali's empire from 1325 to 1375. Sulaiman-Mar, being in the line of Dia/Sunni/Shi rulers, gained back Gao's independence.
After about a century of vicissitudes, “. .also known as ʿAlī Ber (d. 1492). By repulsing a Mossi attack on Timbuktu, the second most important city of Songhai, and by defeating the Dogon and Fulani in the hills of Bandiagara, he had by 1468 rid the empire of any immediate danger. He later evicted the Tuareg from Timbuktu, which they had occupied since 1433, and, after a siege of seven years, took Jenne (Djenné) in 1473 and by 1476 had dominated the lakes region of the middle Niger to the west of Timbuktu. He repulsed a Mossi attack on Walata to the northwest in 1480 and subsequently discouraged raiding by all the inhabitants of the Niger valley’s southern periphery.”
the Benin empire was one of the greatest empires in Africa and the world. they were ruled by a king called an Oba but had an advanced political system in fact according to https://www.everyculture.com
“The kingdom was formerly divided into a number of tribute units, which corresponded to local territorial groupings. Each was controlled by a title holder in Benin City, who acted as the intermediary between the villagers and the king and whose main duty was to collect taxes and tribute in the form of money (cowries) and goods (cattle, yams, etc.). The income the king received from these sources enabled him to carry on elaborate state rituals. The king could also call on villagers to supply labor for the upkeep of the royal palace.”
and according to “The Guardian” “Benin City was also one of the first cities to have a semblance of street lighting. Huge metal lamps, many feet high, were built and placed around the city, especially near the king’s palace. Fueled by palm oil, their burning wicks were lit at night to provide illumination for traffic to and from the palace”
The Oyo kingdom was a Yoruba state the emerged around 1400 and was one of the most dominant kingdoms in the area it was known for their complex military and political system that prevented the king or “Allafin” from having all the power. In fact the http://www.newworldencyclopedia.org says
“The Alaafin, while nominally the sole voice of authority, was unable to exercise complete and unquestioned power. His authority was curbed by the various political institutions of Oyo, particularly the Oyomesi. The Allafin, before making political decisions, was required to consult first with the Oyomesi, which was composed of the heads of the seven non-royal wards of the city. They guided the king in many important matters including military actions and religious festivals.”