Between the two stood Rome, less changed than either North or South—the three terms, Roman, Romano-Byzantine, and Renaissance comprise all the variation she submitted to. In vain the Gothic styles besieged her on the north and the Byzantine on the south. Their waves spent themselves on her rock without producing much impression, while her influence extended more or less over the whole peninsula. It was distinctly felt at Florence and at Pisa on the north and west, though these conquests were nearly balanced by the Byzantine influence which is so distinctly felt at Venice or Padua on the east coast.
The great difficulty in the attempt to reconcile these architectural varieties with the local and ethnographical peculiarities of the people—a difficulty which at first sight appears all but insuperable—is, that sometimes all three styles are found side by side in the same city. This, however, constitutes, in reality, the intrinsic merit of architecture as a guide in these difficulties. What neither the language of the people nor their histories tell us, their arts proclaim in a manner not to be mistaken. Just in that ratio in which the Roman, Byzantine, or Lombardic style prevails in their churches, to that extent did either of these elements exist in the blood of the people. Once thoroughly master the peculiarities of their art, and we can with certainty pronounce when any particular race rose to power, how long its prevalence lasted, and when it was obliterated or fused with some other form.
There is no great difficulty in distinguishing between the Byzantine and the other two styles, so far as the form of dome is concerned. The latter is almost always rounded externally, the former almost always straight-lined. Again: the Byzantine architects never used intersecting vaults for their naves. If forced to use a pointed arch, they did so unwillingly, and it never fitted kindly to their favourite circular forms; the style of their ornamentation was throughout peculiar, and differed in many essential respects from the other two styles.
It is less easy always to discriminate between the Gothic and Lombardic in Italy. We frequently find churches of the two styles built side by side in the same age, both using round arches, and with details not differing essentially from one another. There is one test, however, which is probably in all cases sufficient. Every Gothic church had, or was intended to have, a vault over its central aisle. No early Christian church ever attempted it. The importance of the distinction is apparent throughout. The Gothic churches have clustered piers, tall vaulting-shafts, external and internal buttresses, and are prepared throughout for this necessity of Gothic art. The early Christian churches, on the contrary, have only a range of columns, generally of a pseudo-Corinthian order, between the central and side aisles; internally no vaulting-shafts, and externally only pilasters. Had these architects been competent, as the English were, to invent an ornamental wooden roof, they would perhaps have acted wisely; but though they made several attempts, especially at Verona, they failed signally to devise any mode either of hiding the mere mechanical structure of their roofs or of rendering them ornamental.
Vaulting was, in fact, the real formative idea of the Gothic style, and it continued to be its most marked characteristic during the continuance of the style, not only in Italy, but throughout all Europe.
As it is impossible to treat of these various styles in one sequence, various modes of precedence might be adopted, for each of which good reasons could be given; but the following will probably be found most consonant with the arrangement elsewhere adopted in this work:—
First, to treat of the early Christian style as it prevailed in Italy down to the age of Charlemagne, and to trace out its history down to the 11th century, in order to include all that work executed by Greek artists or copied from it by Lombardic artists; a phase which might appropriately be termed the Byzantine-Lombardic style.
Secondly, to follow the history of the formation of the round-arched style in Lombardy and North Italy, which constitutes the real Lombardic style.
Thirdly, to take up the Byzantine-Romanesque style as it was practised in the centre and South of Italy; because it follows chronologically more closely the art of the North of Italy.
Fourthly, to follow the changes which the influence of the Gothic style exercised in the 13th and 14th centuries in Italy.