An unusual tradition within African sculpture is the cast-metal work done from about the 12th century in what is now southern Nigeria. It reaches a peak of perfection among the Yoruba people of Ife. Between the 12th and the 15th century life-size heads and masks, and smaller full-length figures - all of astonishing realism - are cast in brass and sometimes in pure copper (technically much more difficult). These figures have an extraordinary quiet intensity.

This craft, perfected by the Yoruba people, is continued from the 15th century in Benin - still today a great centre of metal casting. The Benin heads, delightful but less powerful in their impact than those of Ife, are commonly known as Benin bronzes.

In fact they are made of brass, melted down from vessels and ornaments arriving on the trade routes (in 1505-7 alone, the Portuguese agent delivers 12,750 brass bracelets to Benin). The arrival of the Portuguese prompts the Benin sculptors to undertake a new style of work - brass plaques with scenes in relief, in which the Portuguese themselves sometimes feature. These plaques are nailed as decoration to the wooden pillars of the royal palace.