In the political system of the ancient Benin Kingdom (in present-day southern Nigeria), the Queen Mother held the title Iyoba. The Iyoba was one of the most powerful figures in the Benin political hierarchy, second only to the Oba (king) himself.
The institution of the Iyoba was created in the early 16th century by Oba Esigie, who bestowed the title on his mother, Queen Idia, in recognition of her critical role in helping him secure the throne and her contributions during the wars against the Igala people. Queen Idia served as a military strategist and spiritual adviser to her son, and her elevation formalised the political influence of the king's mother in Benin governance.
The Iyoba was given her own palace, her own court, and authority over a designated town. She had the right to commission bronze and ivory works of art, a privilege otherwise reserved for the Oba. The famous ivory mask of Queen Idia, one of the most recognised artefacts of Benin art, was carved in her honour.
The other titles listed belong to different West African political traditions: Iyalode is a title for a female chief in Yoruba towns, Erelu is a female chieftaincy title in Lagos and other Yoruba communities, and Omu is a title for a female leader in certain Igbo communities (particularly in the western Igbo area around Asaba).