The transition from the Roman illuminations to the Byzantine may be traced to the time when Constantine moved his seat of government from Rome to Constantinople.  Constantinople then became the centre of learning, and books were written there in great numbers.  For some centuries Constantinople was the chief city in the art of illuminating.  The style that here grew up exhibited the same features that characterized Byzantine art in mosaic and decoration.  The Oriental influence displayed itself in a lavish use of gold and colour; the remnant of Classical art was slight, but may sometimes be detected in the subjects chosen, and the ideas embodied.  The Greek influence was the strongest.  But the Greek art of the seventh and eighth centuries was not at all like the Classic art of earlier Greece; a conventional type had entered with Christianity, and is chiefly recognized by a stubborn conformity to precedent.  It is difficult to date a Byzantine picture or manuscript, for the same severe hard form that prevailed in the days of Constantine is carried on to-day by the monks of Mt.  Athos, and a Byzantine work of the ninth century is not easily distinguished from one of the fifteenth.  In manuscripts, the caligraphy is often the only feature by which the work can be dated.

In the earlier Byzantine manuscripts there is a larger proportion of Classical influence than in later ones, when the art had taken on its inflexible uniformity of design.  One of the most interesting books in which this classical influence may be seen is in the Imperial Library at Vienna, being a work on Botany, by Dioscorides, written about 400 A. D. The miniatures in this manuscript have many of the characteristics of Roman work.

The pigments used in Byzantine manuscripts are glossy, a great deal of ultramarine being used.  The high lights are usually of gold, applied in sharp glittering lines, and lighting up the picture with very decorative effect.  In large wall mosaics the same characteristics may be noted, and it is often suggested that these gold lines may have originated in an attempt to imitate cloisonne enamel, in which the fine gold line separates the different coloured spaces one from another.  This theory is quite plausible, as cloisonne was made by the Byzantine goldsmiths.

M. Lecoy de la Marche tells us that the first recorded name of an illuminator is that of a woman—­Lala de Cizique, a Greek, who painted on ivory and on parchment in Rome during the first Christian century.  But such a long period elapses between her time and that which we are about to study, that she can here occupy only the position of being referred to as an interesting isolated case.