We know no more than what the well-cut inscription tells us, that he was VICARIUS URBIS ROMÆ, or Vice-Prefect of the city of Rome. But, judging from the style, the good proportions (admitting the convention which made the person of highest rank the largest), the dignified faces, and the natural arrangement of the drapery, it must be of early date, probably towards the end of the fourth century, about the time of the beautiful tablets of the Nicomachi and the Symmachi (No. 58), to which it is closely allied by the well-hung drapery and the surrounding border of delicately cut honeysuckle pattern. [Illustration: [BERLIN MUSEUM 2. SECOND LEAF OF THE DIPTYCH OF PROBIANUS End of fourth century] The top has a slight gable, as in the early diptych of Probus (Fig. 3), No. 2. Probianus is depicted in the Tribunal, sitting on his high-backed throne, surrounded by his clerks, who bear piles of writing tablets, and below, probably outside the _cancelli_ or barrier, which is to be found in all Roman basilicas, stand the litigants, who appear to be congratulating him. Outstretched fingers, in early art, meant the act of speech, and then, as now, congratulatory addresses were inscribed and presented. On the second leaf we see the address on his knee, and by a curious convention he is writing with his own hand the words they acclaim him with, “PROBIANE FLOREAS.” [Illustration: ALINARI PHOTO.] [AOSTA CATHEDRAL 3. FIRST LEAF OF THE DIPTYCH OF PROBUS] In the first leaf he is delivering judgment, and the two lower figures wear the toga, showing they are of high rank, and on the other both he and the litigants are arrayed in the chlamys of ordinary folk. Below, between the litigants is seen a mysterious object on a tripod stand, which some say is the _clepsydra_ or water-clock, and others declare to be the official inkpot. On the right of the Vice-Prefect is a curious standard-like erection called the _vexilla regalia_, on which was painted the portraits of the Emperor and Empress, and which was never absent from any important ceremonial. The diptych first on Molinier’s list covers an antiphonary in the Treasury of the Basilica at Monza, which contains so many other interesting antiquities. Legend tells us that this ivory was sent about the year 600 to the Lombard queen, Theodolinda, by Pope Gregory the Great in acknowledgment of her efforts to convert her very barbaric subjects from the Arian heresy to Catholicism.