But there is scarcely one of these edifices, where remains of them exist or are supposed so to do, which has not been the subject of controversy, the authorship of the Sakhrah (taking that as an instance) having been assigned, by various persons who would usually be considered as authorities on the subject, to the Romans under Constantine, to the Byzantines under Justinian, and to the Arabs under Abd-el-Melek. It becomes, therefore, important to have a clear record as to what Justinian did, not only in Palestine but in other countries, so as to be able to judge to some extent, by well-authenticated examples, of the founders of those edifices whose history is involved in doubt. Of the writers who can give us this record, none has such authority as Procopius, or gives so much detailed information; and he has, for that reason, been largely quoted by Gibbon and by well-nigh every other writer on Byzantine history; and he gives such definite information as to the dates of many of Justinian’s buildings which remain to us, as to form a standard by which to recognise the general characteristics in outline and detail adopted by his architects in his greatest works, and which characterize the style now well known as Byzantine. Its first and greatest example is St. Sofia at Constantinople, which is, perhaps, the boldest instance of a sudden change in almost every respect, whether of plan, elevation, or detail, which is known in architecture. Before its construction, the ground-plan of well-nigh every building known to Western architects had defined the plan of all above it. The columns in the apse of the Basilica, or church, carried galleries or other erections above it, of varied design, but in the same straight or curved lines as those beneath them. The lines of the dome (except in slightly exceptional cases, such as the ruin known as the Temple of Minerva Medica at Rome, or the Temple of the Winds at Athens) were carried up on the distinct lines of the lower walls. The capitals of the columns in the works of the ancient Greeks or Romans were in each building carved on the same design; and however beautiful each might be, the eye would see but one form of the Doric, Ionic, or Corinthian, through the whole range of a colonnade. The Byzantines changed all that. The great dome of St. Sophia (the boldest piece of novel construction ever, perhaps, attempted) forms the crown of a building quite original in plan; and this dome is placed, not as that of the Roman Pantheon, low down on thick walls of its own form, but suspended high above all the roof around it, on four arches, which spring from detached piers, the keystone alone of each arch giving a direct support to the dome; in every other part it overhangs the void in the boldest manner.