This stylies were developed in the fifth century
(exterior) SAN VITALE (interior)
This style was originated in eastern, the name of the Bizantine style comes is Bizantium this is a roman city.
Another roman city is Ravenna, this was occupied by the Ostrogoths and in the reign of Byzantine Emperor Justinian, in this same city we can found the basilica San Vitale, this basilica is made like differents materials: outside have gold and inside with marble but is decorated with mosaics.
Who is Justinian ? He was an emperor that made the Eastern Roman Empire strong was art artistic prominence and political. In a mosaic the artist put in the heads of Teodora and Justinian a halo this represent somthing like spiritual powers that they supposed to have.