High Quality Content by WIKIPEDIA articles! The Libri Carolini ("Charles` books"), Opus Caroli regis contra synodum ("The work of King Charles against the Synod"), also called Charlemagne`s Books or simply the Carolines, are the work in four books composed on the command of Charlemagne, around 790, to refute the supposed conclusions of the Byzantine Second Council of Nicaea (787), particularly as regards its acts and decrees in the matter of sacred images. They are "much the fullest statement of the Western attitude to representational art that has been left to us by the Middle Ages".