The first mosaics were created around 4,000 years ago. They originally were primitive, consisting of terra cotta cones depressed into a background to serve as decorations. The Greeks later turned mosaics into an art form, using colored stones and glass to create geometric patterns and intricate scenes depicting animals and people. Between the fifth and fifteenth centuries, Byzantine mosaics were created that took the art form to a new level. These Byzantine mosaics introduced the use of gold and silver to create a glittering effect and incorporated a new type of tesserae, called smalti.
Tesserae were typically pieces of rock or ceramic made specifically for mosaics. The smalti tesserae used in Byzantine mosaics were manufactured from panels of opaque, colored glass made in Ravenna, Italy. Sometimes these smalti were backed with silver or gold to reflect the light. Mosaics were originally created on panels, but Byzantine artists blended mosaics with architecture by covering the walls and ceilings inside Byzantine churches with the small tiles.
In addition to smalti, Byzantine mosaics incorporated marble, colored stones, terra cotta, and semiprecious gemstones. Different sizes were used, and the mosaics had irregular shapes. The smallest tesserae were used to create faces.
Before applying the mosaics, the surface was covered with plaster followed by a layer of mortar to create a setting bed for the mosaic tiles. The mosaic pieces were then pressed into the mortar and set at oblique angles so that their glassy surfaces would glitter when struck by light. Smalti backed with gold foil were often used to depict halos which seemed to glow with an unearthly radiance.
Most of the artwork created with early Byzantine mosaics was destroyed in the eighth century after the church decreed that icons violated the Ten Commandments. The Church of the Nativity in Bethlehem and the Hagia Sophia in Constantinople contained intricate mosaics that were destroyed during this iconoclastic destruction period. Some notable fragments of early Byzantine mosaics that remain are remnants from the floor of the Great Palace of Constantinople and a piece that was sequestered behind the mortar in the apse of the Church of Santa Maria Formosa.
After the church reversed its position against the use of icons, artwork incorporating Byzantine mosaics became even more intricate and beautiful than before. Western countries also began to practice the artform, but they were never able to achieve the high standard of beauty. After the sacking of Constantinople in the early 13th century, the Byzantine Empire couldn’t afford the high costs of mosaics to decorate its churches and started using paintings instead.