Infinite Geometries: Exploring the Arts of the Medieval Islamic World

In his extension to the Great Mosque of 962-66, Caliph al-Hakam II included a bay with a raised skylight to bring light into the rather dark mosque interior. When the building was converted to Christian use in 1236, this area, with its luminosity and intricate decoration, was chosen as the setting for the high altar of the church. This wall arch is notable for its superimposed polylobed arches. Note how the tripartite design interacts with the 11-lobed main arch above, forming highly unusual irregular negative spaces.