The kingdom of Benin (in present-day Nigeria) was plunged into a state of turmoil at the end of the fifteenth century when oba Ozolua died and left two powerful sons to dispute succession. His son Esigie controlled Benin City while another son, Arhuaran, was based in the equally important city of Udo about twenty miles away. The ensuing civil war severely compromised Benin's status as a regional power and undermined Benin City's place at the political and cultural center of the kingdom. Exploiting this weakness, the neighboring Igala peoples sent warriors across the Benue River to wrest control of Benin's northern territories. Esigie ultimately defeated his brother and conquered the Igala, reestablishing the unity and military strength of the kingdom. His mother Idia received much of the credit for these victories as her political counsel, together with her mystical powers and medicinal knowledge, were viewed as critical elements of Esigie's success on the battlefield. To reward and honor her, Esigie created a new position within the court called the iyoba, or "Queen Mother," which gave her significant political privileges, including a separate residence with its own staff.
As mother of the king, Idia and later iyobas wielded considerable power. Until recent times, the iyoba, who bore the oba's first son, had no other children and devoted her life to raising the future ruler of the kingdom, a role she was destined to play even before her own birth. Queen Mothers were therefore viewed as instrumental to the protection and well-being of the oba and, by extension, the kingdom. Indeed, obas wore carved ivory pendant masks representing the iyoba during ceremonies designed to rid the kingdom of malevolent spiritual forces. An especially fine example of such masks in the Metropolitan Museum's collection dates from the sixteenth century and is believed to depict Idia herself (1978.412.323). Two vertical bars of inlaid iron between the eyes allude to medicine-filled incisions that were one source of Idia's metaphysical power. Within the court, the iyoba's political status was equal to that of a senior chief, and she enjoyed the right to commission precious works of art for personal and devotional use. Images of the iyoba found on the cast brass objects with which she was associated, such as ikegobo (altars to the hand) (1979.206.218) and urhoto (rectangular altarpieces) (1991.17.111), portray her in a shirt of coral beads flanked by attendants bearing symbols of political and spiritual power. These attendants, also depicted in carved ivory (1978.412.302), were women under the tutelage of the iyoba destined for marriage to her son, the future oba. As with ancestral obas, deceased iyobas were venerated with cast brass memorial heads (1977.187.36) fitted with carved ivory tusks and displayed on royal altars.
Bortolot, Alexander Ives. "Idia: The First Queen Mother of Benin". In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. http://www.metmuseum.org/toah/hd/pwmn_3/hd_pwmn_3.htm (October 2003)
These related Museum Bulletin or Journal articles may or may not represent the most current scholarship.