Christian religion was very much at the heart of Byzantine culture, politically, socially and artistically. It was an empire run as a theocracy, ruled by God working through the Emperor, and political ideals were largely informed by Christian values. This permeated visual culture as well, not only in terms of art that was explicitly religious in its purpose. With Christian religion becoming the primary religion across the Byzantine Empire, Christian iconography became an extremely popular decorative motif displayed on many smaller decorative items and wares.
A cross of this sort, could have been worn as a pectoral cross, and was an attribute of bishops during the Middle Ages. The cross was the most popular Christian symbol in Byzantium: it offered protection to the wearer and would have been available all over the Empire, while depiction of saints, angels and the Virgin appeared around the 6th century AD.