Exterior and Apse Mosaic in Cathedal at Cefalù

"Like the Coronation mosaic in the Martorana, Roger's assumption of Frankish ritual and Byzantine regalia signified that his monarchy was responsible to God alone;  it was a declaration of independence from papal political interference."  Eve Borsook, Messages in Mosaic:  The Royal Programmes of Norman Sicily (1130-1187) (Clarendon Studies in the History of Art; Oxford: 1990) 6