The heyday of mosaic making in Sicily was the age of the independent Norman kingdom in the 12th century. The Norman kings adopted the Byzantine tradition of mosaic decoration to enhance the somewhat dubious legality of their rule. Greek masters working in Sicily developed their own style, that shows the influence of Western European and Islamic artistic tendencies. Best examples of Sicilian mosaic art are the Cappella Palatina of Roger II, the Martorana church in Palermo and the cathedrals of Cefalù and Monreale.