Iwu are facial and body markings (scarifications) that were historically worn by Edo men and women. However, since the 1960s, the practice has been nearly extinct (Aisien 2011). In the past, Iwu were used as a way of proving that one was an Edo citizen, and the ceremony of having Iwu completed was an important rite of passage for men and women. The Osiwu, who also practised circumcision and other surgical procedures, would carry out the procedure of adding Iwu. There are different types of Iwu: ‘blades’ worn on the torso (Iwu-eko), and those worn on the face, such as Ikharo (three or four markings above the eyebrows), Irho (two narrow ‘blades’ worn on each cheek), Ovbihue (nasal ‘blades’), Ovbi-agbanmwen (chin ‘blade’), and Igho-okpa/Ukpgho (three forehead ‘blades’) (Aisien 2011, p. 22).

The number of Iwu also varied depending on the identity of the person wearing them. For example, royal men would wear six ‘blades’ on their torso, whilst men who were not royal would wear seven ‘blades’. Meanwhile, the Ọba’s female children would wear fifteen ‘blades’, and all other women would wear sixteen (Aisien 2011).

In the 16th century, Ọba Ẹsigie established the title of Iy'Ọba (Queen Mother) in honour of his mother, Iy'Ọba Idia, for the crucial role she played in the Benin–Idah War (1515–16). She is often described as “the only woman who went to war” ( ).

The Iy'Ọba can usually be identified by her distinctive curved, conical hairstyle, known as Ukpẹ ọkhọkhọ, which is said to have been introduced by Iy'Ọba Idia (Kaplan 1993, p. 58). In addition, the Iy'Ọba was permitted to wear certain items of attire otherwise reserved for the Ọba, such as the Ewu ivie (coral-beaded shirt) and Ukpan obọ eva (crossed coral-beaded baldrics), as well as regalia associated with senior chiefs, including the Odigba (coral-beaded collar) and Udahae (coral-beaded forehead band) ( ).

Representations of the Iy'Ọba appear on ivory Emwin Arhe (royal treasures), including the five famous Uhunmwu-Ẹkuẹ (pendant masks) believed to depict Iy'Ọba Idia, as well as on a number of Aken'ni Elao (carved altar tusks). She is also represented in brass and bronze, including on Ikẹgobọ (altars to the hand) and Urhotọ (altar tableaux) made for Iy'Ọba shrines and altars ( ). In these representations, the Iy'Ọba is often accompanied by female attendants who form part of her retinue.

The Ukpẹ ọkhọkhọ is a distinctive hairstyle and coral-beaded headdress worn by the Iy’Ọba. The headdress includes a projection called the ‘ede Iy’Ọba’, which indicates that “her spiritual potentialities are closer in quality to those of her ruling son than they are to the powers of the nobles” (Aigbe Eson and Ihama Iguneronmwon in Blackmun 1991, p. 60). The Iy’Ọba’s hairstyle and headdress are meant to resemble ukpe-okhue, or the curved parrot’s beak (Kaplan 1993).

Barbara Blackmun (1991, p. 60) argued that “Benin art is multivocal, and any depiction of the Iye Ọba [sic] is a reference to Idia. Every woman who holds the office of lye Ọba plays the part of Idia, the ideal model of an Ọba’s mother.” Wearing the Ukpẹ ọkhọkhọ is one of the ways the Iy’Ọba plays the role of Idia.