Artist thought to be Philoxenos of Eretria or Helen of Egypt (c.310 bc). Alexander the Great Confronts Darius III at the Battle of Issos [mosaic cell located in Pompeii]. Museo Archeològico Nazionale, Naples.

The individual features of both generals are present; the framing motif’s pace is repeated by the spears the hero charges into; canvas is nearly equivalent in positive/negative space and value organization with the upper horizontal block against the lower. There isn’t a value pattern so much as a roughly balanced distribution of the value range in the lower block. A strong design choice is the contrast of curved versus straight shapes and edges. | 
Alexander the Great shown as heroic, a man of action, who leads from the front is the primary purpose behind this mosaic. His figure contrasts against his opponent, who protects himself by surrounding himself by those he commands, letting them fight his battles for him. I believe the panicked poses of the three horses that surround him suggest the fear Xerxes III has in his mind. The canvas is charged with the energy of the moment before two massive forces are about to collide and brutally destroy each other. 

Shapes defined through value adjustments build this work. The texturing native to mosaic as a medium supports this work’s unique character. It is nearly without color, but seems to me that a monochromatic color scheme based on warm red is used. Patterning is present with repeating figurative, round (heads, torsos) and straight-edged (spears) elements. 

A reasonable attempt at plastic depth is made, in opposition to the flat nature of shapes, mainly through overlap and a sort of proto-atmospheric perspective. Details are developed in a manner consistent with ancient artwork. That is, they are consistently defined throughout, and not a crutch used to create depth. 

At first glance, visual elements, and therefore weight, are distributed evenly in the block that contains them. Because the composition is disproportionately horizontal, the potentially destabilizing energy of the action is diluted. The artist has created remarkable organic conflict between the “heroic” left side, which takes up less space but carries the undeniable force of righteousness, and the “villainous” right side, which inverts those two scales (quality of character and pictorial size). Static asymmetry applies. 

Colors are overwhelmingly muddied to the point of near-neutrality. There are also basic neutrals present, resulting in the implication of color differences through value. Figure definition is not organized in nearly the same manner as works typical of the era. This is a strength, because it imitates the chaos of hand-to-hand battle, and infuses the work with a sense of energy that wouldn’t be possible if strict design and specific communication were emphasized more. 

I believe two measures define the primary areas of attention, which are the faces of the conflicting generals. First, their faces are really the only two that are developed to the point where the individual can be identified. Second, in the case of Xerxes, the large, defensive circular element standing out from the field it’s woven into because of the near-white trimming that is used to define it. This further emphasizes the contrasting characters of the two primary subjects. 

In fact, shapes are not decorative but developed in space through modeling. Equally as important, this scene depicts Xerxes III fleeing in defeat. His gesture is one of pleading acceptance, almost begging for mercy. Works such as this one were popular with Roman patrons because it confirms their faith in the moral righteousness of cultures centered on representative government over autocracy. Formally, it masterfully expresses a dramatic, violent event through a seamlessly blended combination of modeling, form arrangement and energy.