These motifs are known as Uhunmwu Ikpotoki in Edo, which translates as ‘Portuguese head’ in English. Portraits of Portuguese men, featuring only their heads and sometimes their shoulders, were used by artists as motifs on the Emwin Arhe (royal treasures), in particular on the Ama-Ẹrọnmwọn (bronze relief plaques) and Aken'ni Elao (carved altar tusks). Also included here are a series of two or three conjoined spirals, which are interpreted as abstract forms of this motif.

One of the earliest suggestions that many of the European figures depicted on objects were Portuguese was made two years after the 1897 British Colonial Military Campaign on Benin City by the British Museum curators Charles Hercules Read and Ormonde Maddock Dalton (1899, p. 19), based on testimony from seven chiefs in the aftermath of the military campaign. The long, straight hair, beards, and domed hats together led to the identification of these representations as Europeans (von Luschan 1919, pp. 54–57; Ezra 1992, p. 246).

When included within the visual imagery of the Emwin Arhe, the Portuguese are associated with the new Atlantic trade and the consequent wealth that emerged following first contact with the Portuguese in the late 15th century. For this reason, Portuguese heads are also often associated with the sea deity Olokun. Eisenhofer (2007, p. 59) argued that the Portuguese figures and heads as motifs on the royal treasures are symbols of the king’s power: “these depictions of foreigners helped to build and strengthen the king’s image.”

When incorporated into the design of the Ama-Ẹrọnmwọn (bronze relief plaques), Curnow (1997, p. 48) instead argued that these motifs could in fact indicate events that took place during Ọba Esigie’s reign. Ọba Esigie is associated with the Portuguese, as they became increasingly important during his reign, assisting with battles against the Igala from Idah, bringing Catholicism to Benin, and introducing weaponry such as guns and cannons, which were instrumental in the expansion of the kingdom.