The author aims to explore the connection between Arabic Islamic and Byzantine cultures during the High Middle Ages as well as the optical theory and practice which made mosaic so spectacular to its medieval viewers. Through examples of mosaic that culminate in the glass works constructed at Cordoba and Orvieto that employed both Byzantine and Islamic workers, we can see the cultural and scientific inheritance of the Hellenic age. Using existing optical theory, the author will elucidate the spiritual and secular reasons behind optically dazzling glass mosaics that appear during the years of cultural interchange between expanding empires. Mosaic work of the medieval world possessed an ability to convey the Divine and was highly prized for its optical complexities.
The trade and even competition between these two large, looming cultures' fostered an environment in the Mediterranean that was highly charged with energy and innovation. By examining methods, production and optical theory we can see the parallel development of mosaic art approaching its medieval zenith. This parallel evolution of cultural, philosophical and scientific research led to an active combination of efforts in the making of great glass religious works in the High Middle Ages.