Geometric and plant motifs were among the most frequently used motifs in Byzantine art. Designed to highlight the subject they framed, the ornamental motifs often became elements that organised the composition, dictating its proportions and balance. They did not circumscribe the form but generated it. The influence of Islamic art enriched the Byzantine repertory with new motifs and intensified their use on larger surfaces.
During the Early Christian period, geometric elements filled the long floor spaces in the basilicas before extending over the lateral walls and other architectural elements. Their forms, solid and robust in appearance, were relatively simple. They spread out in repeating patterns and in various combinations, giving the impression of a multicoloured carpet. Zigzag, strapwork, secant circles and stepped motifs were those used most often and were still in use until a very late period. Squares decorated with fleurons, interlaced circles, folded ribbons and lozenges were arranged symmetrically to form small chains or bands. During the Byzantine era, geometric motifs, having lost their vigorous relief, often became more complicated and were increasingly stylised. “Composite” motifs, such as circles—juxtaposed, secant or joined together by leaves or festoons—as well as stepped squares and lozenges, were very common in the new repertory. Between these geometric designs there could be various combinations decorated with floral elements and stems arranged horizontally or diagonally, enriched with flowers-leaves and other imaginary elements.
Plant and floral motifs comprised the majority of the ornamental decoration of Byzantine art. The artists, eager to create an imaginary world beside the religious programmes of art, devised a new series of adornments that had nothing in common with the realistic elements. Certain embellishments, in frequent use from the early centuries, marked the evolution of ornamental decoration: fleurons, palmettes, foliage, interlacing and heart-shaped motifs.
The fleuron and the palmette were the most widely used motifs and experienced an extraordinary blossoming thanks to the rich and varied possibilities that they made available to artists until the end of the Byzantine Empire. The fleurons, a flower with three to five wide and flat leaves, supported by a small stem, appeared in many forms: the petals are flat or in perspective, separated from one another or joined, the middle of the fleuron is sometimes indicated, and the upper part is detached from the lower part. These three-dimensional plant motifs, which appear in manuscripts and on enamels, were later very popular in the goldsmith’s art and wall decoration. The Sasanian origins of this motif are without question, but it seems that it was once again the folded or flat vine leaf that was behind this change. It is, however, certain that it was in Umayyad art that the vine leaf was transformed.
Another plant motif that was very much in fashion in Byzantine ornamentation was the palmette. A typically Sasanian motif, it flourished again in Islamic art, like so many other Sasanian motifs. Byzantine artists of the Middle Byzantine period adopted this adornment in turn, making use of the variations that existed previously. The palmette, abundantly represented in Byzantine art, was used either vertically—and occasionally upside-down—horizontally, diagonally or superimposed. Its introduction, first in manuscripts and then in other techniques, was an extraordinary event for the artists of the Middle Ages. Palmettes—straight, split, winged or alternating with other stylized plant motifs—all reflect an affinity with Islamic art, even though identical combinations cannot be found. Split palmettes, the most widely used—either in rows, as a filler element or combined with interlacing—appeared as half-leaves with three petals identical to the petals of the palmette.
Vine-leaf scrolls and acanthus leaves also constituted one of the richest and most significant ornamental creations. Foliage, a motif whose rhythm is due to the fluidity of its curves and the alternation of its leaves, was very popular in Hellenistic art and was also used in Early Christian art. The evolution of the foliage scroll is characterised by the different ways in which the leaves are treated and combined to the stems. The combination of heterogeneous elements, particularly that of vine-leaf scrolls with other types of leaves or flowers, is characteristic of Islamic art, in which the motif finally became popular. Much the same thing occurred in Byzantine art, imagination replacing natural phenomena.
Interlacing motifs are considered combinations derived from the classical form of foliage with alternating scrolls. This type of motif featured in both Byzantine art and Sasanian art. But the new characteristics taken on by the interlacing (decorated with half-palmettes or branches) are considered traits of Sasanian art. The use of interlacing started to be very much in fashion in Byzantine art from the eleventh century.
Finally, heart-shaped motifs, hollowed out and containing a palmette or a fleuron, took the form of an ace of spades, a spearhead or an ivy leaf. They are either side by side, joined at the base or at the tip, or linked by festoons. The same motifs sometimes formed veritable networks or arabesques.