It does not appear that the sculpture of historical reliefs was developed much before the time of the Empire; at least, not more of these remain than of the Roman portrait-statues that can be imputed to a more remote period. Historic sculpture was best exhibited in triumphal monuments. To this class belong the two world-renowned columns of Trajan and of Marcus Aurelius. With more than five thousand figures and over two hundred scenes, they are among the most magnificent sculptural representations of all times. Upon these ascending spiral reliefs are unrolled the chronicles of the Dacian and Marcomannic wars. The main events are recognizable throughout, and the barbaric tribes may be distinguished by their costumes, arms, and physiognomy; so that if written history were wanting, the reliefs upon Trajan’s Column would be an important source of information in regard to the biography of this emperor and Roman imperial history. Vigorous in treatment and skilful in drawing as it must be admitted that they are, still their artistic value, from want of style in composition, is very small.

The oblong tablets of relief upon the triumphal arches occupy a somewhat more favorable position, because the frame led to a more formal, and the duplication to a more harmonious, composition. The reliefs upon the Arch of Titus, particularly those on the sides of the two large passages, notwithstanding the ignorance which they betray, are of far higher importance in art; and the same may be said of the reliefs upon the monuments of Hadrian and Trajan. (Fig. 303.) How far the graces of form and order, inherited from the Greeks and hitherto prevalent, had disappeared even in the time of the Antonines, and given place to a formal and vacant hardness, is shown by the relief upon the pedestal of the lost statue of Antoninus Pius. (Fig. 304.) This represents the apotheosis of Antoninus and Faustina, who appear seated upon the back of a stiff, floating Genius of Immortality, in the weakest of compositions, while cold and all-controlling Allegory places by the side of Roma a personification of the Campus Martius, recognizable by the attribute of the obelisk which was erected there by Augustus.

Roman sculpture reached its highest point under Hadrian. This emperor filled all spaces with sculpture, as Trajan covered them with inscriptions commemorating his restorations, acquiring thus, in later times, the nickname of the “Lichen.” Even the golden house of Nero was, in this respect, surpassed by the Villa of Hadrian at Tibur, where it pleased him to reproduce all the wonderful works of architecture and of sculpture which he had noticed in his extended travels through the Roman world. After the death of Hadrian, however, who, as an enthusiastic admirer of Greek art, naturally directed the artistic industry of his time to the best possible reproductions of the highest products of Hellenic art, the Romans began to follow the works of the later ages. The lower they placed their aim, and the farther they were removed from the original source of inspiration the more rapid was their decline.

Ideal art degenerated into increasing formalism, carelessness, weakness of sentiment, and shallowness, though still retaining much that was good, because the originals, though copied and recopied, still dated back to the best periods. Portraiture naturally retained more independence; but this also would have been stifled by the enormous requirements, even if the declining art had possessed fresh vigor. To understand this excessive demand, it is only necessary to bear in mind the rapid succession of emperors after Antoninus, with the consequent changing of imperial statues in all the cities of the Roman empire. With the Antonines expired the ideal element in sculptural portraits; and prosaic realism, as it had existed in ancient Italian art, obtained exclusive mastery. Anxious struggles after external likeness in small and inartistic details, like wrinkles, and abnormities such as the curly and frizzled hair of the Antonines, and of L. Verus, with locks like porous pumice-stone, took the place of the lost ideal—remarkable examples, which failed to preserve the lifelike expression. Within a century art had altogether lost the capacity for characterization, even in portraiture; and the numerous busts of the later empire can hardly be distinguished one from another. They are mostly portraits of emperors, empresses, and princes, whose heads are stiffened and hardened into a common type. Previously, with a change of the sovereign, they had altered the heads of the Achilleic and iconic imperial statues; but it now sufficed merely to vary the inscription, and, at most, the accessories. But it was not difficult to change the face also, since it pleased them, in making busts, to combine marbles of different hues, so as to realize the local colors. Thus the mask was of simple white, the hair of dark marble, the garments of red, green, and gray marble or granite, and even the band for the forehead and the clasp for the toga were of a suitable hue. In the heads of ladies this disagreeable polychromy had the advantage that, upon the portrait of the same sovereign, not only the mask, but the wig, could be altered, which, according to the fashion of the day, might be blond, red, or dark, with any desired mode of dressing the hair.

Carving in relief, after the Antonines, suffered a similar decline. The sculptures upon the Column of Marcus Aurelius, in comparison with those of Trajan’s Column, notwithstanding their unmistakable dependence upon the older example, show the want of energy, of appreciation of form, of variety, and of technical ability which characterizes the loss of creative power, and the mere reproduction of models. The reliefs of the Arch of Marcus Aurelius, once upon the Corso at Rome, now in the palace of the Capitol, betray the same vacuity of expression and hardness of form, in comparison with the illustrations from the life of Trajan upon the Arch of Constantine; even when compared with the sculptures upon the pedestal of the Column of Antoninus Pius, a decline is visible from the time of the older to the younger Antoninus. But even these are superior to the reliefs upon the Arch of Septimius Severus, erected in 201 B.C., which, in the main parts, have a fourfold division, in order to gain space for the utmost possible number of representations. From the nature of the design, the spiral reliefs upon the columns of Trajan and of Marcus Aurelius exhibited such parallel rows, one above another; but here the same method is employed upon a plane surface, although it crowds the subject to such an extent that the figures become insignificant and, at a little distance, indistinct. In these four lines are given scenes of war, not, apparently, so much to celebrate combat and victory in general as to register especial facts, battles fought with various weapons, sieges, capitulations, and the transport of booty. Though many of the details were vigorous, the forms in general tolerably correct, and the technical ability considerable, yet the composition appears barbaric, the grouping awkward, and the filling of the given space, the composition, and the artistic construction altogether unfortunate.

After Septimius Severus, statuesque art degenerated into mere stone-cutting; the portraits are unrecognizable, the reliefs without expression or effect, except, as in Egyptian art, from the number of figures and accessories. In religious sculptures, finally reduced to bungling artisan work, the last spark of Hellenic tradition died out in continued weak copies. In historical reliefs the impulse to create perished with the artistic ability. When large monumental constructions were required, the material was frequently drawn from the works of former emperors; and even in triumphal memorials, like the Arch of Constantine, there was no hesitation in inserting reliefs unmistakably celebrating the deeds of Trajan, or installing statues connected with his conquests upon the Danube, the builders contenting themselves with filling out what was lacking, as in the case of the Victories upon the pedestals of the columns (Fig. 305), and the narrow frieze of reliefs over the side passages. The figures err greatly in proportions: dumpy, formless, and awkward, appearing incapable of motion, they already exemplify that perfect rigidity which, in the following centuries, was to hold sculpture in bondage. Even where the nature of the representations permitted the influence of the old models, the decline of technical ability is striking, as may be seen by comparing these figures with the Victories upon the pedestals of the Arch of Septimius Severus, which, though superficial, are not without a certain style. The folds, for example, look like the holes and lines of the wood-worm; they are simple stripes cut into the garment, without movement or purpose, hard, rough, and hasty, as is the entire treatment.